experiments with carbonated water

37 Water Science Experiments: Fun & Easy

We’ve curated a diverse selection of water related science experiments suitable for all ages, covering topics such as density, surface tension, water purification, and much more.

These hands-on, educational activities will not only deepen your understanding of water’s remarkable properties but also ignite a passion for scientific inquiry.

So, grab your lab coat and let’s dive into the fascinating world of water-based science experiments!

Water Science Experiments

1. walking water science experiment.

This experiment is a simple yet fascinating science experiment that involves observing the capillary action of water. Children can learn a lot from this experiment about the characteristics of water and the capillary action phenomenon. It is also a great approach to promote scientific curiosity and enthusiasm.

Learn more: Walking Water Science Experiment

2. Water Filtration Experiment

A water filtering experiment explains how to purify contaminated water using economical supplies. The experiment’s goal is to educate people about the procedure of water filtration, which is crucial in clearing water of impurities and contaminants so that it is safe to drink.

Learn more: Water Filtration Experiment

3. Water Cycle in a Bag

The water cycle in a bag experiment became to be an enjoyable and useful instructional exercise that helps students understand this idea. Participants in the experiment can observe the many water cycle processes by building a model of the water cycle within a Ziplock bag.

4. Cloud in a Jar

The rain cloud in a jar experiment is a popular instructional project that explains the water cycle and precipitation creation. This experiment is best done as a water experiment since it includes monitoring and understanding how water changes state from a gas (water vapor) to a liquid (rain) and back to a gas.

Learn more: Cloud in a Jar

5. The Rising Water

The rising water using a candle experiment is a wonderful way to teach both adults and children the fundamentals of physics while also giving them an exciting look at the properties of gases and how they interact with liquids.

6. Leak Proof Bag Science Experiment

In the experiment, a plastic bag will be filled with water, and after that, pencils will be inserted through the bag without causing it to leak.

The experiments explain how the plastic bag’s polymer chains stretch and form a barrier that keeps water from dripping through the holes the pencils have produced.

Learn more: Leak Proof Bag Science Experiment

7. Keep Paper Dry Under Water Science Experiment

The experiment is an enjoyable way for demonstrating air pressure and surface tension for both adults and children. It’s an entertaining and engaging technique to increase scientific curiosity and learn about scientific fundamentals.

Learn more: Keep Paper Dry Under Water Science Experiment

8. Frozen Water Science Experiment

The Frozen Water Science Experiment is a fun and engaging project that teaches about the qualities of water and how it behaves when frozen.

You can gain a better knowledge of the science behind the freezing process and investigate how different variables can affect the outcome by carrying out this experiment.

9. Make Ice Stalagmites

10. Bending of Light

A fascinating scientific activity that explores visual principles and how light behaves in different surfaces is the “bending of light” water experiment. This experiment has applications in physics, engineering, and technology in addition to being a fun and interesting method to learn about the characteristics of light.

11. Salt on a Stick

This experiment is an excellent way to catch interest, engage in practical learning, and gain a deeper understanding of the characteristics of water and how they relate to other substances. So the “Salt on Stick” water experiment is definitely worth trying if you’re looking for a fun and educational activity to try!

Learn More: Water Cycle Experiment Salt and Stick

12. Separating Mixture by Evaporation

This method has practical applications in fields like water processing and is employed in a wide range of scientific disciplines, from chemistry to environmental science.

You will better understand the principles determining the behavior of mixtures and the scientific procedures used to separate them by performing this experiment at home.

13. Dancing Spaghetti

Have you ever heard of the dancing spaghetti experiment? It’s a fascinating science experiment that combines simple materials to create a mesmerizing visual display.

The dancing spaghetti experiment is not only entertaining, but it also helps you understand the scientific concepts of chemical reactions, gas production, and acidity levels.

14. Magic Color Changing Potion

The magic color-changing potion experiment with water, vinegar, and baking soda must be tried since it’s an easy home-based scientific experiment that’s entertaining and educational.

This experiment is an excellent way to teach kids about chemical reactions and the characteristics of acids and bases while providing them an interesting and satisfying activity.

15. Traveling Water Experiment

In this experiment, you will use simple objects like straws or strings to make a path for water to pass between two or more containers.

Learn more: Rookie Parenting

16. Dry Erase and Water “Floating Ink” Experiment

The dry-erase and water “floating ink” experiment offers an interesting look at the characteristics of liquids and the laws of buoyancy while also being a great method to educate kids and adults to the fundamentals of science.

Learn more: Dry Erase and Water Floating Ink Experiment

17. Underwater Candle

In this experiment, we will investigate a connection between fire and water and learn about the remarkable factors of an underwater candle.

18. Static Electricity and Water

19. Tornado in a Glass

This captivating experiment will demonstrate how the forces of air and water can combine to create a miniature vortex, resembling a tornado.

Learn more: Tornado in a Glass

20. Make Underwater Magic Sand

Be ready to build a captivating underwater world with the magic sand experiment. This experiment will examine the fascinating characteristics of hydrophobic sand, sometimes referred to as magic sand.

21. Candy Science Experiment

Get ready to taste the rainbow and learn about the science behind it with the Skittles and water experiment! In this fun and colorful experiment, we will explore the concept of solubility and observe how it affects the diffusion of color.

Density Experiments

Density experiments are a useful and instructive approach to learn about the characteristics of matter and the fundamentals of science, and they can serve as a starting point for further exploration into the fascinating world of science.

Density experiments may be carried out with simple materials that can be found in most homes.

This experiment can be a great hands-on learning experience for kids and science lovers of all ages.

22. Super Cool Lava Lamp Experiment

The awesome lava lamp experiment is an entertaining and educational activity that illustrates the concepts of density and chemical reactions. With the help of common household items, this experiment involves making a handmade lava lamp.

Learn more: Lava Lamp Science Experiment

23. Denser Than you Think

Welcome to the fascinating world of density science! The amount of matter in a particular space or volume is known as density, and it is a fundamental concept in science that can be seen everywhere around us.

Understanding density can help us figure out why some objects float while others sink in water, or why certain compounds do not mix.

24. Egg Salt and Water

Learn about the characteristics of water, including its density and buoyancy, and how the addition of salt affects these characteristics through performing this experiment.

25. Hot Water and Cold-Water Density

In this experiment, hot and cold water are put into a container to see how they react to one other’s temperatures and how they interact.

Sound and Water Experiments

Have you ever wondered how sound travels through different mediums? Take a look at these interesting sound and water experiments and learn how sounds and water can affect each other.

26. Home Made Water Xylophone

You can do this simple scientific experiment at home using a few inexpensive ingredients to create a handmade water xylophone.

The experiment demonstrates the science of sound and vibration and demonstrates how changing water concentrations can result in a range of tones and pitches.

Learn more: Home Made Water Xylophone

27. Create Water Forms Using Sound!

A remarkable experiment that exhibits the ability of sound waves to influence and impact the physical world around us is the creation of water formations using sound.

In this experiment, sound waves are used to generate patterns and shapes, resulting in amazing, intricate designs that are fascinating to observe.

28. Sound Makes Water Come Alive 

These experiments consist of using sound waves to create water vibrations, which can result in a variety of dynamic and captivating phenomena.

29. Water Whistle

The water whistle experiment includes blowing air through a straw that is submerged in water to produce a whistle.

This experiment is an excellent way to learn about the characteristics of sound waves and how water can affect them.

Water Surface Tension Experiments

You can observe the effects of surface tension on the behavior of liquids by conducting a surface tension experiment.

By trying these experiments, you can gain a better understanding of the properties of liquids and their behavior and how surface tension affects their behavior.

30. Floating Paperclip

In this experiment, you will put a paper clip on the top of the water and observe it float because of the water’s surface tension.

31. Water Glass Surface Tension

Have you ever noticed how, on some surfaces, water drops may form perfect spheres? The surface tension, which is a characteristic of water and the cohesive force that holds a liquid’s molecules together at its surface, is to blame for this.

32. Camphor Powered Boat

The camphor-powered boat experiment is a fun and fascinating way to explore the principles of chemistry, physics, and fluid mechanics. In this experiment, a miniature boat is used to travel across the water’s surface using camphor tablets.

33. Pepper and Soap Experiment

The pepper in a cloud experiment is a simple and interesting activity that explains the concept of surface tension. This experiment includes adding pepper to a bowl of water and then pouring soap to the mixture, causing the pepper to move away from the soap.

Learn more: Pepper and Soap Experiment

Boiling Water Experiments

Experiments with boiling water are an engaging and informative way to learn about physics, chemistry, and water’s characteristics.

These investigations, which include examining how water behaves when it changes temperature and pressure, can shed light on a variety of scientific phenomena.

It’s important to take the proper safety measures when performing experiments with hot water. Boiling water can produce steam and hot particles that are dangerous to inhale in and can result in severe burns if it comes into contact with skin.

34. Make It Rain

This experiment can be accomplished using basic supplies that can be found in most homes, make it an excellent opportunity for hands-on learning for both kids and science lovers.

Learn more: Make it Rain

35. Fire Water Balloons

Learning about the fundamentals of thermodynamics, the behavior of gases, and the effects of heat on objects are all made possible by this experiment.

36. Boil Water with Ice

The Boiling Water with Ice experiment is an engaging and beneficial approach to learn about temperature and the behavior of water. It can also serve as an introduction for further discovery into the wonderful world of science.

37. Boil Water in a Paper Cup

The “boil water in a cup” experiment is an easier but powerful approach to illustrate the idea of heat transmission by conduction. This experiment is often used in science classes to teach students about thermal conductivity and the physics of heat transfer.

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Kitchen Science Experiments to Try at Home

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Fizzy Acids - what happens when you carbonate water

Part of the show helen's best bits, soda-syphon.jpg.

Ingredients

Instructions

Grate a small amount (2-3 leaves) of raw red cabbage and put it into a glass.  Add some tap water and then mash it up as well as you can.

Strain out the lumps of cabbage to produce a clear solution.  This is your pH indicator, it will behave like litmus changing colour depending on the acidity or alkalinity of your solution (to find out more see this experiment ).

Test some of your tap water by pouring a small amount of indicator (3-4mm) into a glass and adding tap water.  If the solution is bluey purple then you have hard slightly alkaline water, if it is pink then you have slightly acidic water.  We want the water to start off slightly alkaline, so add a little bicarbonate of soda to your tap water until it stops testing pink.

Split your water into two, carbonate half of it, and leave the other half alone.

Now test both the carbonated and uncarbonated water with your red cabbage indicator and see if there is a difference.

You should find that the carbonated water makes the water much more acidic than the straight tap water.

This is the reason why if you taste the carbonated water it has a tangy, sharp - acidic taste.

First a bottle of normal water is added to the indicator, and then some carbonated water from the soda syphon

Explanation

When you carbonate water you are essentially passing high pressure carbon-dioxide through it and a large amount of that carbon dioxide dissolves in the water.

Carbon dioxide is far more soluble in water than are similar gases such as oxygen or nitrogen. It can also react with the water to form dihydrogen carbonate (carbonic acid).

This reaction is reversible, it is continuously occurring in both directions, carbonic acid is being made and destroyed all the time. This means that if you increase the amount of carbon dioxide by increasing the pressure you will increase the speed of the production of carbonic acid reducing the amount of gas.

Similarly if you reduce the pressure you will slow the creation of carbonic acid, but it will keep on splitting up to form carbon dioxide gas. This is why if you rapidly reduce the pressure on a carbonated drink it can rapidly turn into foam (see the lemonade volcano experiment).

Why is the carbonated water acidic?

The hydrogen carbonate can break up (disassociate) in another way, it can split up into a hydrogen ion (H + ) and a hydrogen carbonate (bicarbonate) ion (HCO 3 - ).

Any solution containing a lot of free hydrogen ions is acidic. In fact pH  (the acid-alkali scale) is just an obscure+ measure of the concentration of hydrogen ions in a solution.

The reaction is again reversible so if the amount of hydrogen carbonate reduces so does the amount of acid.

There is naturally carbon dioxide in the air, and this will dissolve in water making it slightly acidic. This is how water can dissolve away limestone to create caves. As we pump more carbon dioxide into the atmosphere it will make water more acidic, this may cause problems for shellfish whose shells are effectively made of limestone.

Are there actually free protons floating around in an acidic solution?

Strictly an H + ion is a hydrogen atom missing an electron - a proton, which does sound unlikely. In fact what happens is that the Hydrogen carbonate reacts with water to form a hydronium ion (H 3 O + ).

But all the maths works out the same if you think of hydrogen ions so mostly chemists do.

+  It is actually pH =  - log 10 ( [concentration of hydrogen ions / mol dm -3 ] ) ... as I may have said, fairly obscure. It so happens that it makes convenient scale and makes other maths easier for chemists.

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Carbon Dioxide Experiments for Kids

Carbon dioxide is a colorless, odorless gas. It's what makes soft drinks fizzy and makes up the air you breathe out. While it is a necessary greenhouse gas that keeps the Earth's oceans from freezing solid, increasing levels of CO2 contribute to global warming, making it a gas worth studying. Simple carbon dioxide experiments will demonstrate to students the scientific method while also teaching principles of chemistry, physics and other areas of science.

Inflating Balloons

Teach students that there is a chemical reaction between vinegar and baking soda, and tell them CO2 is a product of the reaction -- but since you can't see carbon dioxide gas, how can you tell CO2 is released? Set up an experiment by adding 2 tablespoons of baking soda to a balloon using a funnel. Add 8 tablespoons of vinegar to an empty plastic bottle. Put the end of the balloon over the opening of the bottle, being careful not to drop the baking soda into the bottle just yet. Ask students to hypothesize what will happen when the baking soda and vinegar mix and what will happen to the balloon. Let the baking soda drop into the vinegar and watch the balloon inflate. Were the students' hypotheses correct?

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How to tell the difference between alcohol & alkene in labs, science experiments with purple cabbage, ideas for chemistry projects involving iron rusting, science experiments demonstrating how temperature affects enzyme activity, the best ways to make a homemade tornado for a child's science project, bubbling sandwich bags.

Test the acid-base reaction between baking soda and vinegar further by preparing four toilet paper squares filled with 2 tablespoons of baking soda; twist or fold the edges of the toilet paper to seal in the baking soda. Fill one plastic sandwich bag with 4 tablespoons of vinegar, another with 8 tablespoons, another with 12 tablespoons, and a fourth bag with 4 tablespoons vinegar plus 4 tablespoons water. Students should know that the reaction between baking soda and vinegar produces carbon dioxide gas. Ask students to hypothesize what will happen to the plastic bag once the toilet paper and baking soda bombs are added to the vinegar. They should also hypothesize which bag will inflate the most, or if they think the bags will pop, which bag will pop first. Ask if they think the vinegar diluted with water will make a difference. Test your hypotheses by adding the baking soda bombs and quickly sealing the bags; the carbon dioxide makes the bags pop because there's more gas than they can hold. Take this experiment outside to prevent an indoor mess.

Carbon Dioxide and Breathing

Test the acidity of carbon dioxide gas in an experiment using red cabbage juice as a pH indicator. Make red cabbage juice by boiling shredded red cabbage in 2 cups of water for 10 minutes; the juice should be purple. Tell students that the cabbage juice turns blue if exposed to a basic substance, but it turns pink when exposed to an acid. Put 1 teaspoon of cabbage juice into one small plastic cup, labeled "control" and another teaspoon into another cup labeled "test." Put one end of a straw into the test cup. Ask students which color they think the juice will turn when they blow into the other end of the straw. Blow through the straw for a few minutes and watch the juice turn pinker than the control -- does this mean the carbon dioxide you breathe out is acidic or basic? Test this theory further by adding regular water to a cup of cabbage juice and then carbonated water to another cup of cabbage juice.

Soda Explosion

A popular experiment involves diet soda and Mentos candy. Ask students what they think will happen if they add the candy to a two-liter bottle of diet soda. Will this supposed reaction change if there are varying amounts of soda in each bottle, or will the reaction change if you add only two candies instead of four, six or eight? Test these hypotheses by placing four bottles of diet cola on a table outside -- do not conduct this experiment indoors. Test only one variable at a time, so try either varying amounts of soda or candy. The explosion of bubbles occurs because ingredients in the candy break the attraction of water molecules and encourage carbon dioxide bubbles to form.

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Cara Batema is a musician, teacher and writer who specializes in early childhood, special needs and psychology. Since 2010, Batema has been an active writer in the fields of education, parenting, science and health. She holds a bachelor's degree in music therapy and creative writing.

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The Dancing Raisin Experiment

A Fun and Simple Demonstration of Density and Buoyancy

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Raisins may be dehydrated grapes, but when you add a certain liquid to them they become hip-hoppin’ dancers—at least, that's how they look.

To demonstrate the principles of density and buoyancy , all you need is a little carbon dioxide gas to get those raisins doing the jitterbug. To create carbon dioxide in the kitchen you can use baking soda and vinegar or with the less messy (and less predictable) clear, carbonated soda.

This is a low-cost project, and the materials you need are easy to find in the grocery store. They include:

• 2 to 3 clear glasses (depending on how many versions of the experiment you want to run at the same time)
• A box of raisins
• Clear, well-carbonated soda (tonic water, club soda, and Sprite all work well)  or  baking soda, vinegar, and water

Start by asking following question and record the answer on a piece of paper: What do you think happens when you put raisins in soda?

The Dancing Raisins Experiment

Decide whether you want to use soda or baking soda and vinegar to conduct the experiment or if you want to compare what happens in both versions of the experiment.

• Note: For the baking soda and vinegar version of the experiment, you’ll need to fill the glass halfway with water. Add 1 tablespoon of baking soda, stirring to make sure it dissolves completely. Add enough vinegar to make the glass about three-quarters full, then proceed to Step 3.
• Put out one clear glass for every different type of soda you’ll be testing. Try different brands and flavors; anything goes so long as you can see the raisins. Make sure your soda hasn’t gone flat and then fill each glass to the halfway mark.
• Plop a couple of raisins into each glass. Don’t be alarmed if they sink to the bottom; that’s supposed to happen.
• Turn on some dance music and observe the raisins. Soon they should begin dancing their way to the top of the glass.

Observations and Questions to Ask

• What happened when you first dropped the raisins in the glass?
• Why did they sink?
• Once they started "dancing," did the raisins stay at the top?
• What else did you notice happening to the raisins? Did they look different?
• Do you think the same thing would have happened if you put raisins in water?
• What other objects do you think would "dance" in soda?

Scientific Principles at Work

As you observed the raisins, you should have noticed that they initially sank to the bottom of the glass. That’s due to their density, which is greater than that of liquid. But because raisins have a rough, dented surface, they are filled with air pockets. These air pockets attract the carbon dioxide gas in the liquid, creating the little bubbles you should have observed on the surface of the raisins.

The carbon dioxide bubbles increase the volume of each raisin without raising its mass. When the volume increases and the mass does not, the density of the raisins is lowered. The raisins are now less dense than the surrounding fluid, so they rise to the surface.

At the surface, the carbon dioxide bubbles pop and the raisins’ density changes again. That’s why they sink again. The whole process is repeated, making it look as though the raisins are dancing.

Extend the Learning

Try putting the raisins in a jar that has a replaceable lid or directly into a bottle of soda. What happens to the raisins when you put the lid or cap back on? What happens when you take it back off?

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Float or Sink? An at-home lab on density

There is a classic chemistry demonstration that involves placing cans of soda pop in water to see if they float or sink. 1-8  Usually, sugared sodas sink in water while diet sodas float (video 1).

Video 1:   Curious Cans: A Simple, yet Baffling Science Experiment , Tommy Technicium's YouTube Channel (accessed 3/2/2021)

The sinking of cans of sugared sodas can be explained by the fact that sugar water is more dense than pure water, and of course more dense fluids sink below less dense fluids. Yet as seen in Video 1, it is not always the case that cans of sugared soda sink in water (see the video in reference 7 for an explanation of how the regular Coke floated in Video 1). 4-8  To make sense of this behavior, it must be remembered that whether an unopened can of soda floats or sinks depends upon the density of the entire can. The entire can includes the aluminum can itself, the beverage contained in the can, and the gas in the headspace of the soda. Each contributes to the overall density. If the density of the entire unopened can is greater than that of water it will sink, if it is less than the density of water it will float.

An analysis of whether an unopened can will float or sink can be made quantitatively. The method of doing so is simple enough to carry out in your own kitchen if one has access to a digital balance. 9

The density (D full ) of a full, unopened can of soda is equal to the total mass of the unopened soda ( m ror ) divided by its total volume ( V ror ):

The total mass of the unopened can is easy enough to find: just place the unopened can on a balance! Finding the volume of the unopened can is a bit trickier (see reference 8 for a slightly different method than presented here). Notice that the total volume of the unopened can of soda pop is the sum of the volume of the space in the interior of the can ( V i ), and the volume of the metal that makes up the empty can ( V can ):

It is possible to find V can  in a similar manner. First, the mass of the completely emptied can ( m can ) is found. This mass is converted to volume using the density of aluminum ( D Al = 2.7 g mL -1 ):

Substitution of Equations 3 and 4 into Equation 2 allows for the calculation of the volume of the unopened can:

Finally, substitution of Equation 5 into Equation 1 allows us to see how to calculate the density of the unopened can from measured values and the known densities for water and aluminum:

I had students in my non-majors science course (see supporting information for the labsheet I used) test out this method of determining the density of unopened cans of various brands of soda; a total of 37 cans were tested (Table 1). Students first tested the unopened cans of soda to see if they floated or sunk in water. After doing so, they used the method outlined above to determine the density of the unopened can. In 34 of the cans tested, the calculated density was found to be consistent with the observed floating and sinking behavior of the can. For these cans, if the measured density of the can was greater than 1.00 g mL -1 the can sunk, while if the measured density was less than 1.00 g mL -1 the can floated. Of note, cans of Diet Coke, Diet Pepsi, and regular Pepsi all displayed floating and sinking behavior that was consistent with the density that students measured. However, the same was not true for cans of regular Coke. Of the 8 cans of regular Coke tested, 5 cans showed floating and sinking behavior that was entirely consistent with the calculated density. One can of regular Coke exhibited behavior inconsistent with its calculated density: it floated in water, but its calculated density was 1.01 g mL -1 . The remaining two cans of regular Coke had a calculated density that was the same as water: 1.00 g mL -1 . Of these two cans, one floated, while the other sunk. Overall, cans of Diet Pepsi had an average density of 0.975 g mL -1 , cans of Diet Coke averaged 0.980 g mL -1 , cans of regular Coke averaged 1.009 g mL -1 , and cans of regular Pepsi averaged 1.021 g mL -1 .

Table 1: Experimentally determined densities of cans of soda

The method presented here is a variation on a previously published method for determining the density of unopened beverage cans. 8 In this previous method, water displacement was used to determine the volume of the unopened can. The method used herein makes use of mass measurements, which are subsequently converted to the necessary can volume. An advantage of this new method is that it can be accomplished in an at-home setting if a kitchen scale. 9 In my non-majors class we used balances that could measure to the nearest 0.01g, but I surmise one could get good results with a balance that measures to the nearest 0.1g, and fair results with a balance that measures to the nearest gram.

In the experiments presented here, cans of Diet Coke and Diet Pepsi consistently floated, whereas cans of regular Pepsi consistently sunk. Thus, these beverages are preferred if one wishes to demonstrate differences in density between sugared and diet sodas by way of floating and sinking behavior. On the other hand, regular Coke displays differential floating and sinking behavior. Sometimes cans of regular Coke float in water, and sometimes they sink. Therefore, unopened cans of regular Coke have densities that are very close to the density of water. As a result, small changes in the manufacturing of a can of regular Coke (amount of beverage, amount of metal in can, amount of gas in headspace) or experimental conditions (temperature of the water into which the can of Coke is placed) will have noticeable effects on whether a can of regular Coke floats or sinks. Perhaps this is something my students and I will study in the future. I'm also curious about how other beverage brands behave. If you happen to look into the densities of cans of other beverages – or anything else related to this experiment - please let us know. I'd be very inerested to hear what you migth learn.

Happy experimenting!

• Toepker, T. P. Phys. Teach. 1986 , 24 , 164.
• Measure density of the fluid: J. Chem. Educ.   1999 , 76 , 1411.
• J. Chem. Educ.   2006 , 83 , 1632A.
• J. Chem. Educ .  2008 , 85 , 18-19.
• J. Chem. Educ.   2011 , 88 , 272–273.
• https://www.chemedx.org/blog/solution-chemical-mystery-7-curious-cans
• https://www.chemedx.org/blog/chemical-mystery-7-curious-cans
• J. Chem. Educ .  2009 , 86 , 209.
• A balance with a capacity of 500 g and precision of 0.01 g is recommended – but perhaps not entirely necessary. At the time of this writing, balances with these specifications can be purchased at retail stores or on Amazon for $10 - $40.

Unopened 12-ounce cans of regular and Diet Pepsi, water, balance*, large container filled with water.

*A balance with a capacity of 500 g and precision of 0.01 g is recommended – but perhaps not entirely necessary. At the time of this writing, balances with these specifications can be purchased at retail stores or on Amazon for $10 - $40.

• Place an unopened can of Diet Pepsi in a large container of water. Turn the can sideways to make certain no air bubbles are trapped beneath the soda can. Does it float or sink in water?
• Completely dry the can.
• Open the can and completely empty the contents of the can.
• Find the mass of the empty can , m can . Convert this mass to the volume of the can,  V can , using Equation 6.
• Fill the empty space in the can with water. Be sure to completely fill the can to the very top – but don’t overfill! Find the mass of this water, m w . Convert this mass to the volume of the interior of the can, V i , using Equation 5.
• Use Equation 4 (or Equation 7) to find the total volume of the unopened can.
• Use Equation 3 (or Equation 8) to determine the density of the can when it was unopened.
• Based on the density you measured for the unopened can of Diet Pepsi, should the Diet Pepsi float or sink in water? Does this match the observation you made in Step 1?
• Repeat steps 1 – 9 for regular Pepsi.

Data Analysis: Fill in the table below. Pool the results with your classmates.

View the results from the entire class. Based on the calculated densities and observations of floating and sinking in water, does this method of determining the density of an unopened can of soda seem to work well?

Distribute Student Worksheet. 

General Safety

For Laboratory Work:  Please refer to the ACS  Guidelines for Chemical Laboratory Safety in Secondary Schools (2016) .  

For Demonstrations: Please refer to the ACS Division of Chemical Education Safety Guidelines for Chemical Demonstrations .

Other Safety resources

RAMP : Recognize hazards; Assess the risks of hazards; Minimize the risks of hazards; Prepare for emergencies

Ocean Acidification in a Cup

Create a carbon dioxide–rich atmosphere in a cup and watch how it changes the water beneath it. This model of ocean-atmosphere interaction shows how carbon dioxide gas diffuses into water, causing the water to become more acidic. Ocean acidification is a change that can have big consequences. 

Video Demonstration

• Safety goggles
• An acid-base indicator such as bromothymol blue, diluted with water: 8 milliliters bromothymol blue (0.04% aqueous) to 1 liter of water (see the Teaching Tips section below for alternative acid-base indicators, including one made from cabbage juice)
• Two clear 10-oz plastic cups (the tall ones)
• Paper cups, 3-oz size (you’ll only use one in the experiment, but keep a few extras at hand just in case)
• Masking tape
• Plain white paper
• Permanent marker
• Baking soda
• White vinegar
• Two Petri dishes to use as lids for the plastic cups
• Graduated cylinder or measuring spoons
• Gram scale or measuring spoons

• Put on your safety goggles.
• Pour 1 1/2 fluid ounces (40–50 mL) of acid-base indicator solution into each of the two clear plastic cups. 
• Add 1/2 teaspoon (2 grams) of baking soda to the paper cup.
• Tape the paper cup inside one of the clear plastic cups containing the indicator solution so that the top of the paper cup is about 1/2 inch (roughly 1 centimeter) below the top of the plastic cup. Make sure the bottom of the paper cup is not touching the surface of the liquid in the plastic cup—you don’t want the paper cut to get wet. The second plastic cup containing indicator solution will be your control.
• Place both clear plastic cups onto a sheet of white paper and arrange another piece of white paper behind the cups as a backdrop (this makes it easier to see the change).

Position yourself so you are at eye level with the surface of the indicator solution and look closely. What do you see? Where is the color change taking place? 

After a few minutes have passed, you should notice a distinct color change at the surface of the liquid. As you continue to observe the reaction taking place, the liquid in other parts of the cup will also begin to change color.

This activity illustrates how the diffusion of a gas into a liquid can cause ocean acidification. It also models part of the short-term carbon cycle—specifically the interaction between our atmosphere and the ocean’s surface.

Mixing vinegar and baking soda together in the paper cup creates carbon dioxide gas ( CO 2 ). The CO 2  gas then diffuses into the liquid below. When CO 2  gas diffuses into water, the following chemical reaction takes place and results in carbonic acid (H 2 CO 3 ): 

$$\text{CO}_2 (\text{aq}) + \text{H}_2\text{O} \rightarrow \text{H}_2\text{CO}_3$$

Carbonic acid dissociates into H + and HCO 3 - . The increase in H + causes the solution to become more acidic.

Carbonic acid is a weak acid. Even so, the presence of this acid affects the pH of the solution. Thus, after a short time, the surface of the indicator solution changes color: from blue to yellow if you’re using bromothymol blue or from purple to pale pink if you’re using cabbage-juice indicator. This color change indicates a pH change caused by the diffusion of CO 2 gas into the liquid.

Outside of your paper cup, on a much larger scale, atmospheric CO 2 diffuses into the oceans.¹ Oceans are the primary regulator of atmospheric CO 2 . Human activities such as burning fossil fuels and changes in land use have increased the amount of carbon dioxide (CO 2 ) in the atmosphere from 540 gigatons of carbon (Gt C) in pre-industrial times to 800 Gt C in 2015. 

Current atmospheric CO 2  levels are greater than they have been in 800,000 years, and as a result, the fast carbon cycle is no longer in balance. From 1860 to 2009, the oceans absorbed an additional 150 Gt C from the atmosphere.

The CO 2 taken up by the oceans reduces oceanic pH through a series of chemical reactions. The first of these is the reaction you just observed: the creation of carbonic acid via the diffusion of CO 2 gas into water.²

In pre-industrial times, the pH of the oceans was close to 8.2. In 2005, it was approximately 8.1.³ While the pH of the ocean is still basic, it is more acidic than it used to be. Since the pH scale is logarithmic, this means that the oceans are 30% more acidic now than they were in pre-Industrial times.⁴

Diffusion goes both ways—from the atmosphere into a liquid and from a liquid into the atmosphere. This experiment shows passive diffusion: the CO 2 gas diffuses into the liquid. What experiment might you try in order to show that diffusion also goes the other way—from a liquid back into the atmosphere?

In March 2015, the global monthly average of the atmospheric concentration of CO 2 was around 400 parts per million (ppm), or 0.04%. It is a small amount, but it is increasing by more than 2 ppm every year due to the combustion of fossil fuels such as oil, gasoline, natural gas, and coal, as well as land-use changes such as deforestation.

Increases in the concentration of atmospheric CO 2 have led to increases in the concentration of CO 2  and other carbon-containing molecules in seawater. The CO 2 added to seawater reacts with the water molecules to form carbonic acid in a process known as ocean acidification . The oceans are absorbing about 25% of the CO 2 we release into the atmosphere each year. Additionally, as more CO 2 gas enters the atmosphere, the atmosphere gets warmer, causing global temperatures to rise.

Ocean acidification is expected to impact ocean species to varying degrees. Photosynthetic algae and seagrasses may benefit from higher CO 2 conditions in the ocean, as they require CO 2 to live (just like plants on land). On the other hand, studies have shown that a more acidic ocean environment has a dramatic effect on some calcifying species including oysters, shellfish, clams, sea urchins, shallow water corals, deep sea corals, and calcareous plankton. When shelled organisms are at risk, the entire food web may also be at risk.

Our understanding of the phenomenon explored in this Science Snack is built on the work of many scientists.

Dr. Katsuko Saruhashi was a groundbreaking Japanese geochemist responsible for two important techniques that help scientists understand the global effects of rising carbon dioxide levels. In 1957, Dr. Saruhashi was the first woman to earn a doctorate from the University of Tokyo (then called the Imperial Women’s College of Science). She went on to develop a process for accurately measuring carbon dioxide in water; this methodology, called "Saruhashi’s Table," was essential for demonstrating that global warming would not be substantially curbed by ocean water’s capacity to absorb carbon dioxide, and continues to be used globally today. She also developed methods and tools for tracking radioactive fallout across oceans, ultimately leading to the reduction of oceanic nuclear experimentation. She was the first woman elected to the Science Council of Japan in 1980, the first to win the Miyake Prize in geochemistry in 1985, and in 1981, she established the Saruhashi Prize, which continues to inspire and honor young women in the natural sciences today. You can measure the concentration of carbon dioxide in water using a different method than Dr. Saruhashi's with the Ocean Acidification in a Cup Science Snack.

Prior to trying Ocean Acidification in a Cup, learners should be familiar with acid-base indicators and know that baking soda and vinegar create CO 2 gas when mixed. This lesson dovetails with lessons on surface interactions and diffusion.

Making your cabbage-juice indicator If bromothymol blue indicator is hard to come by, or if you’d prefer not to use this chemical in your classroom, you can use cabbage-juice indicator instead. It’s easy to make: Just take a quarter of a head of purple cabbage, place it in a blender with water to cover, and blend until you get a uniform puree. Strain the resulting mixture—the purple liquid you’re left with is your cabbage-juice indicator. Dilute it with some water and proceed with the experiment, using it instead of bromothymol blue. You will need to experiment with the ratio of water to cabbage juice to see what dilution gives you good results. Note that unlike bromothymol blue, cabbage-juice indicator turns pink, not yellow, in the presence of an acid.

References:

• Dr. Jürgen Schieber (Indiana University, Geology 1425 course notes):  Chapter 8: The Importance of Carbon for Climate Regulation 
• Mathez, E. A. (2009). Climate Change: The Science of Global Warming and Our Energy Future . Columbia University Press, New York. 
• NOAA Ocean Acidification Program: What is Ocean Acidification (OA)?
• NOAA PMEL Carbon Program:  What is Ocean Acidification?                                            

Thanks to Chris Sabine of NOAA’s Pacific Marine Environmental Lab and t o Jim Bishop of University of California at Berkeley for sharing their expertise.

Related Snacks

• For Teachers

• Everyday Activities
• Experiments

Dancing Raisins

Learn about density and displacement with this fun, easy experiment. Turn on some tunes and discover how raisins bust a move!

Activity adapted from PBS Kids for Parents .

You Will Need

Clear carbonated liquid (sparkling water or clear soda work well)

Tall clear glass

• Fill the glass 3/4 full with the carbonated liquid. Make some observations. What do you see?
• Now drop a raisin into the glass. What do you notice? At first, the raisin sinks, but then something changes. What’s happening?
• Look closely at the raisin and make some more observations. What do you see all over the raisin? What happens next? Who taught that raisin how to dance?

How it works

This experiment demonstrates how an object’s density can change. At first, the raisin sinks because its density is greater than the carbonated liquid. Then the carbon dioxide bubbles stick to all of the little creases of the raisin and increase the raisin’s volume. This helps it to displace more liquid and up it goes! Its density is now less than the liquid and it floats to the top. Once it reaches the top, the gas bubbles pop, the raisin’s volume decreases, and it falls back down and the cycle starts all over again.

Displacement is what happens to the liquid when an object gets dropped in. Think about when you get into the bathtub - have you ever noticed that the water level rises after you get in? You are now taking up space in the tub, and the water has to move out of the way or get displaced, in order to make room for you.

Carbonated Water & Mint Science Experiment Step-by-Step Tutorial with Pictures!

This shop has been compensated by Collective Bias, Inc. and its advertiser.   All opinions are mine alone.  #SummerHydration  #CollectiveBias

Calling all future scientists and budding chemists!  I know the perfect summer science experiment just for you!  It is called the Carbonated Water & Mint Science Experiment .  It is easy to do too!   All you need are 3 products that can be found at your local grocery store.

First, head out to your local store and purchase the following supplies:

• 1- Honest Tea Bottle
• 1- Bottle of Tonic Water
• 1- Pack of Mints made of Gelatin and Gum Arabic

I got all of my personal supplies for this science experiment at Alberston’s, a local grocery store chain in Southern California.

Here is the Carbonated Water & Mint Science Experiment Step-by-Step Tutorial:

1. The first step of the experiment is to pour the tonic water into the recyclable Honest Tea bottle.

2. Next add a mint into the bottle of tonic water.  The more mints you add, the more foam you will create.

Remember though, only the mints that contain gelatin and gum arabic will create this type of chemical reaction.  You can easily find these types of mints at your local grocery store as well.

3. Finally, sit back and relax and watch the bottle do its magic!  This is my children’s favorite part of the science experiment.  The more mints you add to the bottle, the greater the chemical reaction you will create!

The theory behind this experiment is that a mint made with gelatin and gum arabic expedites a rapid release of carbon dioxide when dropped into a carbonated liquid, such as a tonic water.  CO 2,  in combination with the gelatin and gum arabic ingredients of the mints, contribute to the formation of the foam.

Have fun and explore the foam with your kids!  Ask them questions such as “What will happen if you add one mint?” or “What will happen if you add ten more?”  Let your children play with the science experiment until their little hearts are content.  You are building a future scientist here!  It takes time!

While shopping for my supplies for this science experiment, I also purchased a variety of drinks from Albertson’s to help keep my family well hydrated this summer.  In California, it can get up to 105 degrees in the summer.  Therefore, I thought there was no better time than the present to stock up on drinks.

So I picked up some POWERADE in the sports drink aisle and Gold Peak Tea and Honest Tea in the drink aisle.  I sure do love a cold ice tea on a warm summer night!

And right now if you purchase at least $10 worth of the products listed below, you will receive a coupon for $4 off your next purchase that will print out at the register.

• 6 pack – vitaminwater (20 ounces)
• 6 pack – smartwater (700ml)
• Honest Tea (59 ounces)
• Gold Peak Tea (64 ounces)
• POWERADE (32 ounces)

Tell us what science experiments you plan to do with an Honest Tea bottle this summer!  I look forward to hearing all about them!

Thursday 16th of July 2015

What a fun experiment! Thank you so much for sharing! My kids will love it! #client

Science in School

An ocean in the school lab: carbon dioxide at sea teach article.

Author(s): Carla Isabel Ribeiro, Ole Ahlgren

Did you know that carbon dioxide dissolves in bodies of water and affects the ocean? Explore the effect of carbon dioxide on ocean chemistry with these practical activities.

Chemistry of carbon dioxide in the ocean

The ocean plays an important role in the Earth’s climate. Although it is a complex system, interconnecting all parts of the globe, the ocean obeys simple laws of physics and chemistry that can be used to raise awareness of the dynamics of the ocean and its impact on our lives.

The increasing concentration of carbon dioxide in the Earth’s atmosphere due to human activities, like burning fossil fuels (main source of anthropogenic carbon dioxide), changes the atmosphere and makes the ocean more acidic. The topic of ocean acidification naturally ties into the curriculum topics of acids and bases, pH, and even precipitation reactions.

Rain is naturally acidic (pH around 5.6) because it dissolves carbon dioxide from the atmosphere to form carbonic acid:

Unlike rain, the ocean is alkaline (pH slightly above 8) because it contains carbonates and hydrogen carbonate ions. The ocean is thus an important repository of anthropogenic carbon dioxide, removing it from the atmosphere. This might seem like a good thing, but it results in lower pH and changes to the ocean’s chemistry. Acidification of the ocean affects the availability of carbonate ions, an important component of shells. Carbon dioxide is dissolved in the ocean to form carbonic acid, which reacts with carbonate ions. Thus, amounts of carbonate ions decrease and hydrogen carbonate ions increase:

Activity 1: Carbon dioxide and water pH – Part I

This experiment shows how carbon dioxide changes the pH of the water and why the rain is naturally acidic. The colour changes of the universal indicators make the experiment more appealing to younger students.

• 2 Erlenmeyer flasks (100 cm 3 )
• Fresh water (40 cm 3 )
• Universal indicator or bromothymol blue (5 to 7 drops)

The colours of the indicators are shown in figure 1. In all figures shown here, bromothymol blue is used.

• Students fill the flask with 40 cm 3 fresh water. You can also try this with sea water or make your own by dissolving about 3.5 g of sea salt in 100 cm 3 of water.
• Add drops of pH indicator to each flask and measure the pH.
• In one flask, using a straw, slowly blow air into the water.
• Students should observe changes in colour (figure 2) and note the new pH values.

Activity 2: Carbon dioxide and water pH – Part II

Carbon dioxide is not bubbled into the ocean. Contact between the ocean and the atmosphere is enough for the gas to be dissolved. This experiment is a better representation of what happens naturally in the ocean, but the results are not so immediate.

• 250 cm 3 beaker with rubber stopper
• 250 cm 3 Erlenmeyer flask
• 50 cm 3 tap water with about 10 drops of universal indicator or bromothymol blue
• 10 cm 3 Vinegar (acetic acid)
• Baking soda (2 tablespoons)
• Matches (optional)
• Students add the vinegar slowly to about 2 teaspoons of baking soda in the Erlenmeyer flask (figure 3). When fizzing stops, students can test if the beaker is full of carbon dioxide by placing a lit match in it. The match will go out in the presence of CO 2 .
• Students then ‘pour’ the gas into a beaker, containing 50 cm 3 water with indicator, which is then closed with the rubber stopper.
• Carbon dioxide will slowly dissolve in water, but it can take up to a day to observe any change in pH (figure 3).

Activity 3: Carbon dioxide from burning wood

An alternative to Activity 2 involves burning a wooden stick, for example, a match, to produce carbon dioxide above the surface of water. This scenario is closer to the real-life burning of fossil fuels and will produce similar results.

• 100 cm 3 Erlenmeyer flask with rubber stopper
• 20 cm 3 tap water with about 5 drops of universal indicator
• Wooden stick
• Students put 20 cm 3 water containing indicator into the flask and measure the pH.
• Students must wear safety glasses. A small wooden stick is ignited and held down into the flask (figure 4) until the flame is extinguished due to a lack of sufficient oxygen to sustain combustion.
• The flask is closed using the stopper and shaken for a few seconds.
• The indicator changes colour, and the pH of water is measured again (figure 4).
• When shaking the flask, CO 2 is quickly absorbed by the water. In real life, this is a slow process. To illustrate this, repeat without shaking and leave the stoppered flask at rest for several hours to see the colour change when CO 2 is absorbed.

Safety note

Students should wear safety glasses during this activity.

Activity 4: Carbon dioxide and carbonate ions

This experiment will qualitatively reveal the amount of carbonate available in solution.

Calcium carbonate is insoluble in water, unlike calcium hydrogen carbonate, which is very soluble. When we add calcium ions (from a calcium nitrate solution) to a solution with carbonate ions (from a sodium carbonate solution), we should observe the formation of a white precipitate of calcium carbonate, one of the constituents of seashells. If we lower the pH, we can observe how this affects the amount of carbonate available in the solution by the amount of calcium carbonate that precipitates.

Materials and reagents

• Na 2 CO 3 (0.05 mol/dm 3 solution (0.52 g Na 2 CO 3 in 100 cm 3 H 2 O)
• HNO 3 (1 mol/dm 3 solution)
• Ca(NO 3 ) 2 (0.03 mol/dm 3 solution (0.33 g Ca(NO 3 ) 2 in 100 cm 3 H 2 O))
• 3 test tubes
• pH meter or pH test strips
• Students add 5 cm 3 Na 2 CO 3 solution to each of three test tubes (A, B, and C; figure 5).
• Add 10 drops of HNO 3 solution to tube A, 5 drops to tube B, and none to tube C (control).
• With the pH meter or test strip, measure the pH in each tube and then add 1 cm 3 Ca(NO 3 ) 2 solution (or around 25 drops) to each tube.
• Students then observe the results and reach a conclusion regarding which solution has more carbonate available for precipitation as calcium carbonate. 

For younger students, the results can be explained in a simpler way by saying that water has dissolved carbonate ions (CO 3 2- ), hydrogen carbonate ions (HCO 3 – ), and carbonic acid (H 2 CO 3 ). The last one can be converted into water and carbon dioxide. The relative amount of each species depends on the pH of the solution. In the solution with lower pH, there are very few carbonates and more carbonic acid, which is decomposed, so we can see carbon dioxide forming. For older students, the results can be explained in a more complex way using the following chemical equations, the concepts of chemical equilibrium, and Le Chatelier’s principle.

After dissolving CaCO 3 in water (solution with high pH):   

After adding HNO 3 :

A more acidic solution shifts the equilibrium to the right, so, according to Le Chatelier’s principle, less is available. In tube A, the equilibrium is shifted so far to the right that CO 2 is observed by the formation of bubbles.

After adding Ca(NO 3 ) 2 :

The solution with the most white precipitate will be the one with most carbonate ions available; in this case, it is tube C, which contains sodium carbonate (pH=11) and no nitric acid (HNO 3 ).

Consequences for ocean life

The increase in atmospheric carbon dioxide due to human activity has an impact on the ocean. About 30% of this gas is absorbed by the ocean and a fraction reacts with the water to form carbonic acid. This weak acid causes acidification of the ocean by lowering the pH. The term ocean acidification, despite being correct, might be misleading, since the ocean is alkaline with a pH of around 8.1 (figure 6). [ 1 ]

But, even if the ocean remains alkaline, a drop in pH affects biochemical reactions within an organism and the formation of structures in calcareous marine organisms. [ 2 , 3 ]

According to figure 6, as the pH drops, the amount of carbonate ions drops as well, making them less available. Carbonate ions are transformed into hydrogen carbonate ions and carbon dioxide. This is why in Activity 4, at pH 7, the formation of a gas is observed.

Questions to ask students

• Why does the water in Activity 1 change colour when blowing into it?
• How does the experiment in Activity 3 illustrate a consequence of burning fossil fuels?
• Explain the difference in precipitates in the three test tubes in Activity 4 based on figure 5 and figure 6.
• People sometimes illustrate a consequence of the acidification of the ocean by putting shells into acid. Why is this experiment misleading?
• If the pH of the ocean drops from 8.1 to 8.0, by approximately how much will the ratio of carbonate ions decrease, according to figure 6?

[1] An article on ocean acidification by the National Oceanic and Atmospheric Administration (NOAA): https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification

[2] A report on the consequences of ocean acidification: https://worldoceanreview.com/en/wor-1/ocean-chemistry/acidification/

[3] A report on how climate change alters ocean chemistry: https://worldoceanreview.com/en/wor-1/ocean-chemistry/

• Try more ocean-related activities: Ribeiro C I, Ahlgren O (2021) An ocean in the school lab: rising sea levels . Science in School 53 .
• Learn more about how ocean acidification affects seal life: Korn A (2016) Opening seashells to reveal climate secrets . Science in School 35 :12–14.
• Read about the role of our oceans in climate change: Harrison T, Khan A, Shallcross D (2017) Climate change: why the oceans matter . Science in School 39 : 12–15.
• Find out about the physics at work beneath the waves with these classroom experiments: Watt S (2012) Movers and shakers: physics in the oceans . Science in School 25 : 28–33.
• Explore other chemistry experiments relevant to climate change: Shallcross D, Harrison T (2008) Practical demonstrations to augment climate change lessons. Science in School 10 :46–50.
• Read about the impact of human activity on climate change and its consequences for the Earth: Follows M (2019) Ten things that affect our climate . Science in School 47 :19–25.
• Find out how the consequences of climate change are already having an impact on communities: Unwin H (2020) The social science of climate change . Science in School 49 :18–22.
• Find related hands-on activities at Earth Learning Idea .

Carla Isabel Ribeiro teaches chemistry and physics at a secondary school in Portugal, and Ole Ahlgren is a retired Danish teacher of physics, chemistry, and biology. The authors have already collaborated and published other experiments in Science in School .

Carbon dioxide and its impacts are rarely out of the news. In this article, Ribeiro and Ahlgren bring together three simple practicals to help underpin the teaching of the chemistry involved as the world’s oceans dissolve carbon dioxide.

Through increasing complexity, the authors explore a range of important ideas including: the differences in acidity between sea water and drinking water, the impact of dissolving carbon dioxide on pH and finally looking at the equilibria between carbonate and hydrogencarbonate ions. Their final experiment offers useful extensions for more gifted students providing a way into discussions about Le Chatelier.These experiments should offer teachers a useful addition to the explanation of what is often seen as a more theoretical part of the curriculum.

Dr Chris Millington, Teacher of Chemistry, Oldham Hulme Grammar, UK

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The reaction of carbon dioxide with water

In association with Nuffield Foundation

• No comments

In this experiment, students use their own exhaled breath to explore the reaction between carbon dioxide and water. 

This is a relatively brief and straightforward exploration of the reaction of carbon dioxide and water at a simple level, which should take no more than 15 minutes.

When carbon dioxide reacts with water a weak acid is formed. Carbon dioxide present in exhaled air is blown into a flask containing an indicator sensitive to small changes of pH in the appropriate region of the pH scale, and the consequent colour changes observed and recorded. The equation for the reaction between carbon dioxide and water may be introduced for appropriate students.

If students have not yet met the compositions of inhaled and exhaled air, this experiment can serve as part of the learning sequence for the topic of breathing and respiration in an introductory science course, using an appropriately elementary approach to the chemistry involved.

For students who have already covered the topic of breathing and respiration, and know that carbon dioxide is a significant component of exhaled air, the focus in this experiment can be transferred to the nature of the chemical reaction (other related topics could be acid rain, gas liquid reactions or indicators).

The equation for the reaction between carbon dioxide and water may be introduced for appropriate students.

• Eye protection
• Conical flask, 250 cm 3 , x2
• Indicator bottles with dropping pipettes, x3
• Ethanol (IDA – Industrial Denatured Alcohol) (HIGHLY FLAMMABLE, HARMFUL)
• Thymolphthalein indicator solution (HIGHLY FLAMMABLE), access to small bottle with dropper
• Phenol red indicator solution (HIGHLY FLAMMABLE), access to small bottle with dropper
• Sodium hydroxide solution, 0.4 M (IRRITANT), small bottle with dropper
• Distilled (or deionised) water, 125 cm 3 , x2

Health, safety and technical notes

• Read our standard health and safety guidance .
• Wear eye protection throughout.
• Phenol red indicator – see CLEAPSS Hazcard HC032 . The indicator may be purchased as a solid reagent or as a ready-made solution in ethanol. The solution may be made from the solid reagents by preparing a 5% w/v solution in ethanol (IDA). If 30 cm 3  or 60 cm 3  dropping bottles with integral dropping pipettes are available, these are ideal for dispensing the indicator solutions. While phenol red itself is not flammable, its solution in ethanol is highly flammable.
• Thymolphthalein indicator – see CLEAPSS Hazcard HC032 . The indicator may be purchased as a solid reagent or as a ready-made solution in ethanol. The solution may be made from the solid reagents by preparing a 5% w/v solution in ethanol (IDA). If 30 cm 3  or 60 cm 3  dropping bottles with integral dropping pipettes are available, these are ideal for dispensing the indicator solutions. While thymolphthalein itself is not flammable, its solution in ethanol is highly flammable.
• Ethanol (IDA – Industrial Denatured Alcohol), CH 3 CH 2 OH(l), (HIGHLY FLAMMABLE, HARMFUL) – see CLEAPSS Hazcard HC040A .
• Sodium hydroxide solution, NaOH(aq), (IRRITANT at concentration used) – see CLEAPSS Hazcard HC091a  and CLEAPSS Recipe Book RB085.

Source: Royal Society of Chemistry

• Place about 125 cm 3 of water in a 250 cm 3 conical flask.
• Add five or six drops of thymolphthalein indicator to the water.
• Add just enough sodium hydroxide solution (about two or three drops) to produce a blue colour.
• Talk or blow gently into the flask – ie add the carbon dioxide.
• Continue adding the carbon dioxide until a colour change is observed.
• Add one or two drops of phenol red to the water.
• Add two drops of sodium hydroxide solution to produce a red solution.
• Talk or blow gently into the flask – ie add carbon dioxide.

Questions for the class

• Why does the colour change not occur instantly?
• What is the reason for adding a few drops of sodium hydroxide solution (NaOH) before each experiment? 

Answers to questions

• The amount of carbon dioxide in each breath is small, so it takes a lot of breaths to react with the alkali.
• To ensure the solution is slightly alkaline at the beginning and to neutralise any CO 2  or any other acid initially present.

Teaching notes

Straws are not necessary for blowing exhaled air into the flask; simply breathing or speaking into the flask is sufficient to cause the indicator to change colour.

Phenol red indicator changes from yellow to red over the pH range 6.8–8.4. Thymolphthalein (the alternative bromothymol blue could also be used) changes from blue (alkaline) to colourless (acid) over the pH range 9.3–10.5. See CLEAPSS Recipe Book RB000, which also covers bicarbonate indicator solution.

Eventually sufficient carbon dioxide from the students’ breath dissolves and produces enough acid in the solution to change the colour of the indicator:

CO 2 (aq) + H 2 O(l) ⇌ H + (aq) + HCO 3 – (aq)

CO 2  also reacts with NaOH. This reaction produces the less alkaline Na 2 CO 3 :

2NaOH(aq) + CO 2 (g) → Na 2 CO 3 (aq) + H 2 O(l)

The equilibrium between carbon dioxide and water can be reversed by heating the weakly acidic solution to just below boiling. The solubility of carbon dioxide in water decreases as the temperature is raised, and it is driven off into the atmosphere. The concentration of dissolved carbon dioxide therefore drops, causing the equilibrium to shift to the left and the indicator colour to change back to red. On cooling the solution and blowing exhaled breath into the flask again, the sequence can be repeated.

More resources

Add context and inspire your learners with our short career videos showing how chemistry is making a difference .

Additional information

This is a resource from the  Practical Chemistry project , developed by the Nuffield Foundation and the Royal Society of Chemistry.

Practical Chemistry activities accompany  Practical Physics  and  Practical Biology .

© Nuffield Foundation and the Royal Society of Chemistry

• 11-14 years
• 14-16 years
• 16-18 years
• Practical experiments
• Acids and bases
• Reactions and synthesis

Specification

• Soluble non-metal oxides dissolve in water forming acidic solutions
• (a) combustion reaction of alkanes and benefits and drawbacks relating to the use of fossil fuels, including formation of carbon dioxide, acidic gases and carbon monoxide
• (f) the roles of respiration, combustion and photosynthesis in the maintenance of the levels of oxygen and carbon dioxide in the atmosphere
• 2.9.9 investigate the chemical reactions of carbon dioxide with water producing carbonic acid and with calcium hydroxide (limewater) until carbon dioxide is in excess; and
• Carbon dioxide as an acidic oxide.
• Carbon dioxide in water - free and combined as carbonate and hydrogencarbonate.
• Demonstration of the effect of carbon dioxide on universal indicator solution.

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30 Easy Water Experiments For Kids

Water experiments aren’t just for summer! Water is easy and budget-friendly for science learning with preschoolers, elementary-age kids, and even middle school science. Check out our list of our favorite science experiments with water and look for the free printable water themed science camp week guide!

SCIENCE EXPERIMENTS WITH WATER

What do all these science experiments and STEM projects below have in common? They all use water!

These water experiments are perfect for at home and in the classroom with simple household items like salt. Also, check out our science experiments with baking soda.

Let’s dig in if you want to explore science with water as the main ingredient! While you’re at it, make sure to check out more kid-friendly science experiments.

Our science activities and experiments are designed with you, the parent or teacher, in mind! Easy to set up, and quick to do, most activities will take only 15 to 30 minutes to complete and are heaps of fun!

USING THE SCIENTIFIC METHOD

The scientific method is a process or method of research. A problem is identified, information about the problem is gathered, a hypothesis or question is formulated from the information, and the hypothesis is put to the test with an experiment to prove or disprove its validity. Sounds heavy…

What in the world does that mean?!? The scientific method should be used as a guide to help lead the process.

You don’t need to try and solve the world’s biggest science questions! The scientific method is all about studying and learning things right around you.

As kids develop practices that involve creating, gathering data evaluating, analyzing, and communicating, they can apply these critical thinking skills to any situation. To learn more about the scientific method and how to use it, click here.

Even though the scientific method feels like it is just for big kids…

This method can be used with kids of all ages! Have a casual conversation with younger kiddos or do a more formal notebook entry with older kiddos!

Click here to get your 12 days of science challenge calendar!

WATER EXPERIMENTS FOR KIDS

Click on each link below to explore cool experiments with water! Here you will find easy water experiments for preschoolers through middleschoolers, including the water cycle.

This age group is beginning to learn about core concepts in chemistry , including states of matter, how different substances mix or interact, and the properties of different materials.

ICE IS NICE SCIENCE

Explore the solid form of water and ice. Look at three great ice experiments that highlight the scientific method perfectly!

BENDING WATER

Can you bend water? Yes, you can with static electricity. Grab a balloon and some water to set up this easy experiment.

CANDLE IN WATER EXPERIMENT

Can you make the water rise by burning a candle under a jar? Grab a few simple supplies and find out.

CELERY EXPERIMENT

Here’s a simple explanation of how osmosis works with celery and water and a fun science demonstration!

COFFEE FILTER FLOWERS

Water is the main ingredient in this gorgeous but super easy combined science and art activity. Make a bouquet of colorful, coffee-filter flowers and explore solubility too!

COLOR CHANGING FLOWERS

This engaging color-changing flower experiment explores the concept of capillary action as your flowers magically turn from white to green. Easy to set up and perfect for a group of kiddos to do at the same time or as an interesting water science fair project.

CRUSHED SODA CAN EXPERIMENT

What happens when you heat and cool water inside a soda can?

DISSOLVING CANDY

There are all kinds of fun things you can dissolve in water!

DRY-ERASE MARKER EXPERIMENT

Is it magic or is it science? Create a dry-erase drawing and watch it float in water.

FREEZING WATER EXPERIMENT

Will it freeze? What happens to the freezing point of water when you add salt? Check out this easy water experiment to find out.

GROW A RAINBOW

A fun and colorful experiment that uses a paper towel, markers and water to demonstrate the process of capillary action.

GUMMY BEAR OSMOSIS LAB

Learn about the process of osmosis when you try this easy gummy bear osmosis experiment. Watch your gummy bears grow as you investigate what liquid makes them grow the biggest.

HOW DO SHARKS FLOAT?

Explore buoyancy with this simple oil and water experiment.

HOW MANY DROPS OF WATER ON A PENNY?

All you need for this experiment are a few coins, an eyedropper or pipette, and water! How many drops fit on the surface of a penny? What else could you use? A bottle cap turned over, a flat LEGO piece, or another small, smooth surface! Take a guess at how many drops it will take and then test it out.

ICE FISHING

Did you know you can go fishing indoors with salt, string, and ice! Kids will have a blast!

ICE MELT ACTIVITIES

Playful hands on science and learning which is perfect for our preschoolers. Explore water science with one of these fun theme ice melt activities.

LEGO WATER EXPERIMENT

Build a dam from Lego bricks and explore the flow of water.

OCEAN CURRENTS

Build a simple model of the ocean currents with ice and water.

OCEAN LAYERS

Just like layers of the earth, the ocean has layers too! Have you ever wondered how you could see them without going scuba diving in the ocean? Explore the layers of the ocean with a liquid density tower experiment for kids. 

OIL AND WATER EXPERIMENT

Do the oil and water mix? Explore the densities of liquids with this simple oil and water experiment.

POTATO OSMOSIS LAB

Explore what happens to potato when you put them in concentration salt water and then pure water. Learn about osmosis when you try this fun potato osmosis experiment with the kids.

RAINBOW IN A JAR

Can you make a rainbow in a jar? This neat rainbow water experiment explores water density with just a few materials. Instead of salt we use sugar and food coloring to stack the colors of the rainbow.

PENNY BOAT CHALLENGE

Design a simple tin foil boat, and see how many pennies it can hold before it sinks in the water. How many pennies will it take to make your boat sink?

MAKE A PADDLE BOAT

Fill the kiddie pool or tun with water and make this DIY paddle boat for fun physics!

SALT LAVA LAMP EXPERIMENT

Explore what happens when you add salt to oil and water.

SALTWATER DENSITY EXPERIMENT

Can you make an egg float? Will different items sink in freshwater but float in saltwater? Compare saltwater to freshwater with a fun experiment with salt and water. Make your predictions and test your results.

SINK OR FLOAT EXPERIMENT

Check out what you have in the kitchen for an easy science experiment with water   with some very interesting results!

SKITTLES EXPERIMENT

A super simple water science experiment with everyone’s favorite candy! Did you know you can try it with M&Ms too? You can also you those red and white mints, old candy canes, and even jelly beans!

SOAP POWERED BOAT EXPERIMENT

Explore surface tension as kids observe firsthand how soap influences the movement of a small boat on the water’s surface.

SOLID LIQUID GAS EXPERIMENT

Learn about the properties of solids, liquids and gases with this simple water experiment. Have fun observing how water changes from a solid to a liquid to a gas.

STRAW BOATS

Design a boat made from nothing but straws and tape, and see how many items it can hold before it sinks in the water. Explore buoyancy while you test out your engineering skills.

TOOTHPICK STARS

Make a star out of broken toothpicks by only adding water. Learn about capillary action with a totally do-able water experiment.

WALKING WATER EXPERIMENT

Can water walk? Make a colorful rainbow with a little color theory mixed in too! This walking water experiment is super easy and fun to set up! Mason jars, plastic cups, or bowls will also work just fine for this experiment.

WATER CYCLE IN A BOTTLE

Make a discovery bottle all about the water cycle. One of the best water science activities is one where we can learn more about one of the most important and necessary cycles on Earth, the water cycle!

WATER CYCLE IN A BAG

The water cycle is important because it’s how water gets to all the plants, animals and even us!! Learn about the water cycle with this easy water cycle in a bag experiment.

WATER DISPLACEMENT EXPERIMENT

Add this simple water displacement experiment to your science lesson plans this season. Learn about water displacement and what it measures.

WATER EVAPORATION EXPERIMENT

Dive into the process of evaporation (a liquid changes to a gas) with this simple water evaporation experiment. Investigate how different factors like temperature, airflow, and surface area affect the evaporation rate.

WATER REFRACTION EXPERIMENT

Why do objects look different in water? A simple water experiment that shows how light bends or refracts as it moves through water.

WATER XYLOPHONE

A homemade water xylophone is perfect for exploring physics and sound science!

WATER ABSORBTION EXPERIMENT

This is a very simple and fun water experiment which is great for preschoolers. My son had a blast exploring what materials absorb water and what don’t.

WHAT DISSOLVES IN WATER

This is super simple chemistry using common items around the house to explore mixtures and discover which items dissolve in water !

Compare how fast different everyday items melt in the sun, including ice cubes. A fun experiment to do in the summer!

WATER WHEEL

Hop on this engineering project and design a water wheel that moves! Use our idea as a springboard to create your own or follow the step-by-step directions.

WATER CLOCK

Find out how to use water to tell the time with this water clock project .

Plan a Water Summer Science Camp

Grab this free guide and plan a day or two of water theme science camp activities . We have 12 free guides, each with a different theme! Use them all year long.

ALSO TRY THESE EASY SCIENCE EXPERIMENTS

• States of Matter Experiments
• Surface Tension of Water Experiments
• Chemistry Experiments
• Physics Experiments
• Fizzing Experiments
• Physical Changes
• All About Atoms

MORE HELPFUL SCIENCE RESOURCES

Science vocabulary.

It is never too early to introduce some fantastic science words to kids. Get them started with a printable science vocabulary word list . You will want to incorporate these simple science terms into your next science lesson!

WHAT IS A SCIENTIST

Think like a scientist! Act like a scientist! Scientists like you and me are also curious about the world around them. Learn about the different types of scientists and what they do to increase their understanding of their specific areas of interest. Read What Is A Scientist

SCIENCE BOOKS FOR KIDS

Sometimes the best way to introduce science concepts is through a colorfully illustrated book with characters your kids can relate to! Check out this fantastic list of science books that are teacher approved and get ready to spark curiosity and exploration!

SCIENCE PRACTICES

A new approach to teaching science is called the Best Science Practices. These eight science and engineering practices are less structured and allow for a more free**-**flowing approach to problem-solving and finding answers to questions. These skills are critical to developing future engineers, inventors, and scientists!

Printable Science Projects Pack

If you’re looking to grab all of our printable science projects in one convenient place plus exclusive worksheets and bonuses like a STEAM Project pack, our Science Project Pack is what you need! Over 300+ Pages!

• 90+ classic science activities  with journal pages, supply lists, set up and process, and science information.  NEW! Activity-specific observation pages!
• Best science practices posters  and our original science method process folders for extra alternatives!
• Be a Collector activities pack  introduces kids to the world of making collections through the eyes of a scientist. What will they collect first?
• Know the Words Science vocabulary pack  includes flashcards, crosswords, and word searches that illuminate keywords in the experiments!
• My science journal writing prompts  explore what it means to be a scientist!!
• Bonus STEAM Project Pack:  Art meets science with doable projects!
• Bonus Quick Grab Packs for Biology, Earth Science, Chemistry, and Physics
• Science Fair Project Pack with experiments to try!

this site is the best i got an A on my assignment

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Middle School Chemical Engineering For Girls

Great Activities for Middle School Outreach in Chemical Engineering

The Alka Seltzer Reaction

Introduction & motivation.

Chemical reactions are one of the primary focuses for Chemical Engineers. From synthesizing polymers to treating water to creating fertilizers, chemical reactions are important in nearly every aspect of daily life. One job of Chemical Engineers is to classify, understand, and control these reactions to speed them up or slow them down.

Chemical reactions occur when bonds within molecules are broken or formed. There are several things that signify that a chemical reaction took place. These include a change in color, the production of a gas or solid, and of course a change in chemical composition. The starting chemicals before a reaction are called the reactants , and the chemicals that are produced are called the products . The reaction in this activity involves using sodium bicarbonate and citric acid to produce water and carbon dioxide.

Reaction : HCO 3 – (aq) + H + (aq) → H 2 O (l) + CO 2 (g)

The tablets contain sodium bicarbonate (NaHCO 3 ) and citric acid. When the tablet is dissolved in water, bicarbonate (HCO 3 – ) and hydrogen ions (H + ) are formed. Once in solution, the two chemicals can then react according to the reaction listed above. For the reaction to occur, the HCO 3 – and H + must collide at the right angle with the right amount of energy. The chances of this happening are better when the tablet is crushed into more pieces since the molecules have more opportunities to collide and when the temperature is higher, since the molecules are moving faster.

In this activity, students will experiment with the reaction between Alka Seltzer tablets and water in different conditions. By changing temperature and the surface area available for reaction, students will begin to see what factors chemical engineers can control to get the desired result.

This activity introduces the reaction used for the Alka Seltzer Rockets activity, so it is typically performed before building rockets to understand the nature of the reaction before using it.

Chemical Safety:

• Sodium Bicarbonate
• Alka Seltzer tablets
• Large beakers
• Food coloring
• Stopwatches
• Metal spoons
• Thermometers

Before the experiment, ask students to hypothesize what will make the reaction go the fastest and what makes them think that. This can be anything, but try to seek answers with specific regard to the variables being changed in this activity.

The Effect of Temperature on Rate of Reaction

• Partially fill a large beaker with ice cubes. Fill the beaker with water up to the 250 mL mark with cold water and stir the ice water until the temperature equilibrates.
• Measure the temperature of the water and record it in the table.
• Add a tablet and record the time it takes for the tablet to react.
• Repeat 1-2 with room temperature water, then with hot water heated to 70 degrees C using a hot plate.

The Effect of Surface Area on Rate of Reaction

• A whole tablet
• A tablet broken into quarters
• A tablet ground into powder: Place the tablet it a piece of weighing paper (wax or parchment paper work as well) and break it either with your hands or crush it using the back of a metal spoon.
• Add 250 mL of water to a large beaker.
• Measure and record the temperature of the water and make sure it is consistent between trials.
• One student should be ready with a stopwatch and another student should be ready with the whole tablet. The student with the stopwatch should count to three and on three start the stopwatch. At the same time, the other student should drop the tablet into the water.
• Gently stir the water at a consistent speed and pattern.
• As soon as the last of the tablet disappears, yell “Stop!,” stop the stopwatch, and record the time in the table.
• Repeat Steps 2-6 with the quartered tablet and the crushed tablet.

At the end, collect and present all class data on the board. Highlight discrepancies and the general trend.

• Which combination of factors made the reaction go the fastest? The slowest? (Higher surface area and temperature make the reaction go faster. Since the reaction occurs on the surface of the tablet pieces, more access to it will make the reaction go faster because there are more molecules to make bumping together more likely. Higher temperature gives more energy to the molecules, meaning they are more likely to have enough energy for the reaction to continue. The opposite is true for the slowest rate – low surface area and temperature.)
• Why would we want reactions to happen faster or slower? (e.g. we want rusting reactions to be slower to protect metal products, but we want redox reactions that recharge our phone batteries to be fast.)
• Is there a limit to how fast we can make the reaction? Would we want to place a limit if there is not a physical one? (Reactions have maximum rates for a few reasons, like the amount of surface area available to react, if the mixture makes it difficult for molecules to move, etc. If the rate were increased too high, it becomes a safety concern! Sometimes reactions get too fast, too hot, and can’t be slowed down. This is a dangerous runaway reaction , the last thing a chemical engineer wants!)
• Why did any discrepancies come up in the data? What ways could we make our process better to limit those from affecting the class data as a whole? (Discrepancies come up from human error with measuring time, not having precise sizes of tablets, imprecise temperature control across trials, and how hard it is to see a reaction is finished! Let students get creative with suggesting improvements, but a few could include using a grid and knives to chop up tablets or putting the ground tablets through a sieve, using a robot to stir and observe the reaction, and putting the beakers in water baths.)
• We know Alka Seltzer is a medicine to make us feel better. Why might it be designed to fizz? (Fizzing helps the aspirin in the tablet quickly absorb into the bloodstream, making the medicine fast-acting. It might also make it more appetizing to drink!)

Additional Resources

• How Does Alka Seltzer Work?
• VIDEO: Why Does Alka Seltzer Fizz?
• ← Alka Seltzer Rockets
• Separations Activity →

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Table of Contents

“Exploring Fizz and Fun: The Seltzer Water Experiment!”

Introduction

Exploring the science behind seltzer water experiments.

The science behind seltzer water experiments primarily revolves around the process of carbonation. This process involves dissolving carbon dioxide gas under pressure into water, which results in the formation of carbonic acid. This weak acid breaks down into water and carbon dioxide, creating the characteristic bubbles that make seltzer water effervescent. The carbonation process is reversible, meaning the carbon dioxide can be released from the water under certain conditions, such as a decrease in pressure or an increase in temperature. This principle forms the basis of many seltzer water experiments.

One popular experiment involves shaking a bottle of seltzer water and observing the resulting eruption when the bottle is opened. This experiment demonstrates the principle of gas solubility, which states that gases are more soluble in liquids at high pressures. When the bottle is shaken, the pressure inside increases, causing more carbon dioxide to dissolve. However, when the bottle is opened, the pressure decreases rapidly, causing the dissolved carbon dioxide to escape as gas bubbles, resulting in an eruption.

Another interesting experiment involves adding a piece of fruit to a glass of seltzer water and observing what happens. The fruit initially sinks to the bottom due to its higher density compared to the water. However, as the carbon dioxide bubbles attach to the surface of the fruit, its overall density decreases, causing it to rise to the surface. This experiment illustrates the principle of buoyancy, which states that an object will float if its density is less than the fluid it is submerged in.

Furthermore, seltzer water experiments can be used to investigate the effect of temperature on gas solubility. By comparing the amount of fizz produced by a cold and a warm bottle of seltzer water, one can observe that gases are more soluble in cold liquids. This is because the kinetic energy of the gas molecules decreases at lower temperatures, making them more likely to be captured by the liquid molecules and dissolve.

The Role of Seltzer Water in Innovative Home Experiments

To begin with, seltzer water is a product of the process of carbonation, which involves the dissolution of carbon dioxide gas under pressure in water. This process results in the formation of carbonic acid, which gives the water its characteristic fizz and tangy taste. The carbonation process is a classic example of a physical change, where the water changes its state but not its chemical composition. This makes seltzer water an excellent tool for demonstrating the concept of physical changes in a fun and engaging way.

Furthermore, seltzer water can be used to explore the concept of density. By comparing the behavior of an egg in regular water and seltzer water, one can observe that the egg sinks in regular water but floats in seltzer water. This is because the carbonation process increases the density of the water, making it easier for the egg to float. This experiment provides a hands-on way to understand the concept of density, which is a fundamental principle in science.

Understanding Chemical Reactions through Seltzer Water Experiments

Understanding chemical reactions can be a complex task, especially for those who are new to the world of chemistry. However, one of the most effective ways to grasp these concepts is through hands-on experiments. One such experiment involves the use of seltzer water, a carbonated beverage that can provide a fascinating insight into the world of chemical reactions.

This experiment can be taken a step further by adding an acid, such as vinegar, to the mixture. The vinegar reacts with the baking soda to produce even more carbon dioxide gas, resulting in a vigorous fizzing and foaming reaction. This is an example of an acid-base reaction, one of the most common types of chemical reactions.

In addition, the experiment shows how temperature affects the rate of a chemical reaction. The reaction between the seltzer water and baking soda occurs more quickly at higher temperatures, as the increased kinetic energy of the particles allows them to collide more frequently and with greater force.

Seltzer Water Experiments: A Fun Approach to Learning Science

One of the most common experiments involving seltzer water is the exploration of gas solubility. This experiment demonstrates how temperature affects the solubility of gas in a liquid. By chilling one bottle of seltzer water and leaving another at room temperature, then opening both, one can observe that the warmer bottle fizzes more. This is because gas is less soluble in warmer water, causing more carbon dioxide to escape when the bottle is opened. This experiment provides a practical demonstration of a fundamental concept in chemistry, making the abstract idea more tangible and easier to understand.

Furthermore, seltzer water can be used to explore the concept of acid-base reactions. Seltzer water is slightly acidic due to the presence of carbonic acid, formed when carbon dioxide dissolves in water. By adding a base such as baking soda to seltzer water, one can observe a reaction that produces more carbon dioxide gas, causing the mixture to fizz. This experiment provides a hands-on experience of acid-base reactions, reinforcing the concept in a memorable way.

2. Question: What does this experiment demonstrate? Answer: This experiment demonstrates the principle of buoyancy. The raisin sinks in the water initially because it is denser than the water. But when carbon dioxide bubbles attach to it, the raisin becomes less dense than the water, causing it to float.

The seltzer water experiment concluded that seltzer water, due to its carbonation, can significantly affect various factors such as plant growth, digestion in humans, and the corrosion of materials. The carbon dioxide in seltzer water makes it more acidic than regular water, which can have both beneficial and detrimental effects depending on its application.

Carbonated Water Experiments

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Pretty fun experiment and great writeup. It's true it works, however, overall the use of carbonated mineral water is not sustainable in the long run (especially if you have a large tank), and can be dangerous to fish. Unless one is gradually injecting the carbonated water over the course of a day, the results can be disasterous. 1) Too much carbonated water at once can drop pH 2) Adds minerals (sodium) and requires waterchanges 3) Carbonation from an open bottle will go flat quickly (requiring another purchase of a new bottle) 4) Requires slow injection of gas/liquid 5) Expensive compared to other CO2 methods Seachem Excel and DIY CO2 are very effective, and cheap ways of getting that much needed CO2 into the aquarium. They are more sustainable, and I would say more effective. -John N.  

interesting... I thought about this myself. Pearling isn't clue for plant growth though. It could have been from the diffuse CO2 in the water. You should do more experiments on the actual growth of a plant over a month on perrier or canada dry.  

That's what I plan on doing. I'll probably do a 50% water change each week, pouring 2 liters of Canada Dry in on monday, WC on Sunday, repeat. Sound like a decent experiment?  

2 liters? Sounds like a lot. You sould add a little everyday for obvious reasons. Try to aim for 30ppm. I tried to measure CO2 on carbonated water once and it was off the charts so I couldn't get an accurate number.  

If I had the resources (ie, know-how) I'd tip the bottle upside down and set it on some sort of slow-drip. If anyone cares to explain to me how it'd be possible to get maybe 1 drop every couple of seconds, I'd gladly give it a shot and let everyone know how it's goes. The only reason I haven't so far is because I don't really know how I'd go about doing it.  

What do you think about this? You can use a micro ball valve mounted between your bottle's tubing and the tubing going into the aquarium? Then mount the bottle upside down and use the valve to control the flow.  

this sounds like a great experiment. correct me if i am wrong. you are actually putting carbonated water into the tank? or using tubing like you would on diy co2 and letting the excess gases go through the tube and into the tank? sorry i am not very technical so hopefully you will understand my question.  

I'm not technical myself, so I understood perfectly. =P With the Perrier water (first experiment) I emptied a bit of water from my tank, and replaced it with straight carbonated mineral water. Straight from the Perrier bottle. In the second one (with the Canada Dry water) I basically just replaced the DIY C02 bottle with the Canada Dry bottle full of their "original" sparkling water. The tubing was just right above the water-line in the bottle, and hoped the excess gases went through the tubing into the tank. And it seems it did. Today, the airstone isn't bubbling as much, but rather every 3 or 4 seconds bubbling, and then stopping. And bubbling again 4 seconds later, and stopping again.  

I can do that! I'll look around some places for some small ball valves, and then do a week or two test with that setup. Thank you very much, I wouldn't have thought of it myself. I do suspect that this will work better/longer than simply dumping in a certain amount at once, or anything else I've tried.  

You're welcome, TI  

There will be pressure behind the carbonated water that will drop fairly fast that you will be dripping into the tank so that will have to be taken into consideration as it will be a lot at first then not so much later. Would be a whole lot of tinkering. Also in that type of system if it isnt below the waterline then most of the CO2 will be outgassed by the time it actually gets to the aquarium.  

this is brilliant! im going to try some things myself....!  

I have often wondered about using carbonated water as the starter water for the yeast setups... to offset that initial wait period.  

ok, ok, this is just for fun, and you have to understand, that none of this occured to me before and ive never had co2 in any of my tanks... also, im sitting here watching it just in case any problems should occur i dont have any carbonated water, but i had a can of sprite, which i dont like, and with the addition of soem things lying around....ta da, i have co2 in my tank for the first time i took a can kozi, called a can condom, it fits very snuggly around a can of soda and is made of some sort of vynal or rubber.... i poked a small hole in it and and ran airline tubing through it, and also used a small clear paint container as a bell, the pressure wasn't enough for an airstone so....im getting about one bubble every 6 seconds its a one gallon heavily planted tank, i dont know if it will be enough to make the plants pearl more then they already do...im just having fun... i wish i had a camera  

I used "soda water" for about a year. It's a great way to easily (not really cheaply) add co2. There's no danger of the water becoming too acid as carbonated water has... surprise... carbonated in it that will buffer the pH. I'd dump in about a liter or 2 in a 70 gal tank. I seem to recall working out the math once and this was about right. Hooking up a bottle and running the gas into a diffuser is bloody clever. I wish I'd thought of that.  

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