GOLD

Cool Carbonation

Over four days I tested the pH of different water after I blowed into different bottles, and carbonated a bottle over different days and times.
Halina Prosser
Grade 6

Hypothesis

If you add carbon dioxide (CO2) to water (H2O), then it increases the acidity levels in the water, because it takes both those things to form carbonic acid (H2CO3).

 

Research

Background Research:

Introduction

My experiment is about researching carbonated water. Several people have also wondered about the texture and taste of the water. It is important to note that the carbonation process that I studied is not the same as soda water, which is created using sodium bicarbonate and hydrogen dioxide. In order to understand more about my hypothesis, if you add carbon dioxide (CO2) to water (H2O),then it increases acidity levels in the water, I researched the chemistry of mixing carbon dioxide and water, I researched the mechanics on how people make carbonated water, and I researched the experience people have when they drink carbonated water.

Chemistry       

My project is about carbon dioxide (CO2) and water (H20). Carbon dioxide is a colorless, odorless, and non-flammable gas that is one of the most present gasses in our atmosphere. It can exist in solid, liquid, or gaseous states and is used in many chemical processes. H2O is the chemical formula for water. Water forms the planet's streams, lakes, oceans, and rain. It also is the main part of living beings body fluid.

Carbonic acid also forms the liquid that we know as carbonated water. Although this type of acid is weak, it is an essential part of the carbonation process. The question that I ask explores the type of changes the H2O undergoes. It focuses on the amount of change that occurs as the carbonic acid is created and how the acidity levels change.

Mechanics

There are different ways to carbonate water. Water can be carbonated through breath expiration, or mechanically with a CO2 tank. When humans breathe in they inhale air with lots of oxygen. The oxygen is fuel our bodies use to process our food and give us energy. This process generates carbon dioxide, which our bodies cannot use, so it is a waste product which we breath out when we exhale. Humans can make carbonated water by exhaling air through a straw into water. Carbonating water mechanically means to combine highly pressurized CO2 tank with H2O using a regulator. The regulator is a valve that controls the amount of CO2 that is released into the H2O. Normally, the gas regulator valve should be set at 55 PSI (Pounds Per Square Inch). This enables the serving pressure of the carbonated water to remain at around 12 PSI over time. Many commercial CO2 tanks gas regulator valves are set to approximately 20 PSI instead of 55 PSI. This means that the drinks are served at a much lower carbonation pressure rate.

Experience

The carbonation process changes the taste of the water and gives it a bitter taste. This bitterness is caused by the acid when the carbon dioxide dissolves in the water and then reacts with the water, forming carbonic acid. Contrary to some opinions, carbonated water hydrates your body just as well as regular water. This confusion may be due to the mixing up soda water with carbonated water. Carbonated water reduces the feeling of needing to always clear the throat, to feel full for a longer period of time after meals, to assist in digestion functions, and improve heart health. Serving carbonated water to kids may make them more hydrated as it is a fun way to drink water, and they may drink more.

Conclusion

Through exploring the chemistry, the mechanics, and the experience of how carbonated water is created we understand more about the process. Seeing how the carbonic acid amount changes in different situations and how the carbonated water caused by the carbon dioxide helps to understand the chemical processes. In understanding the mechanics of adding carbon dioxide to hydrogen dioxide, we see that humans and machines can create carbonated water using different methods. In exploring the experiences of drinking carbonated water, it is suggested that sparkling water hydrates your body just as well as regular water and does many other amazing things for you as well. This is why I am doing this as my project. I believe that this will be a very fun and informative experiment.

 

Variables

Variables (Manipulated, Responding, Controlled)

  • Manipulated variable: Breath, Water, Time 
  • Responding variable: pH Levels (acidity levels)
  • Controlled variables: Location, Temperature, Beakers, Straw, SodaStream

Procedure

Procedure

Set-Up

  1. Label 6 identical size beakers (example: Beaker 1, Beaker 2, etc…)
  2. Put all the beakers on a table that is accessible and undisturbed
  3. Create a chart to record the possible change in acidity (pH) level

Day 1

  1. Fill beakers 1, 2 and 3 with 450 mls of distilled water
  2. Beaker 1 is the control, so will not receive any carbon dioxide
  3. Take one of your pH strips and place it on your plate
  4. Test the starting pH of the water in beaker 1 by using an eyedropper to get 2-3 drops of the water from beaker one then place it on a new pH strip. The pH strip should be soaked through with water.
  5. Replace any remaining water in eyedropper back into beaker 1.
  6. Record the acidity by comparing the colour in the pH strip to the Key guide of acidity levels.
  7. Repeat steps 6-9 using a dry pH strip with beaker 2 & 3.
  8. Using a straw gently blow into beaker 2 water for 10 seconds
  9. Test the pH and record the acidity level.
  10. Repeat step 11 and step 12 eleven more times.
  11. Put the lid back on beaker 2 and put it back with the rest of the beakers
  12. Move to beaker 3 (Sodastream bottle)
  13. Place beaker 3 in your Sodastream machine and carbonate the water for 10 seconds
  14. Test the pH and record the acidity level.
  15. Repeat step 16 and step 17 eleven more times with beaker 3.
  16. Put the lid back on beaker 3 and put it back with the rest of the beakers

Day 2

  1. Fill beaker 4 with 450 mls of distilled water
  2. To measure the starting acidity repeat steps 6-9 using a dry pH strip with beaker 1, 2, 3, & 4.
  3. Open beaker 2
  4. Using a straw gently blow into beaker 2 water for 10 seconds
  5. Test the pH and record the acidity level.
  6. Repeat step 23 and step 24 eleven more times.
  7. Put the lid back on beaker 2 and put it back with the rest of the beakers
  8. Open to beaker 3 (Sodastream bottle)
  9. Place beaker 3 in your Sodastream machine and carbonate the water for 10 seconds
  10. Test the pH and record the acidity level.
  11. Repeat step 28 and step 29 eleven more times with beaker 3.
  12. Put the lid back on beaker 3 and put it back with the rest of the beakers
  13. Open beaker 4
  14. Using a straw gently blow into beaker 4 water for 10 seconds
  15. Test the pH and record the acidity level.
  16. Repeat step 33 and step 34 eleven more times.
  17.  Put the lid back on beaker 4 and put it back with the rest of the beakers

Day 3

  1. Fill beaker 5 with 450 mls of distilled water
  2. To measure the starting acidity repeat steps 6-9 using a dry pH strip with beaker 1, 2, 3, 4 & 5.
  3. Open beaker 2
  4. Using a straw gently blow into beaker 2 water for 10 seconds
  5. Test the pH and record the acidity level.
  6. Repeat step 40 and step 41 eleven more times.
  7. Put the lid back on beaker 2 and put it back with the rest of the beakers
  8. Open to beaker 3 (Sodastream bottle)
  9. Place beaker 3 in your Sodastream machine and carbonate the water for 10 seconds
  10. Test the pH and record the acidity level
  11. lRepeat step 45 and step 46 eleven more times with beaker 3.
  12. Put the lid back on beaker 3 and put it back with the rest of the beakers
  13. Open beaker 4
  14. Using a straw gently blow into beaker 4 water for 10 seconds
  15. Test the pH and record the acidity level.
  16. Repeat step 50 and step 51 eleven more times.
  17. Put the lid back on beaker 4 and put it back with the rest of the beakers
  18. Open beaker 5
  19. Using a straw gently blow into beaker 5 water for 10 seconds
  20. Test the pH and record the acidity level.
  21. Repeat step 55 and step 56 eleven more times.
  22. Put the lid back on beaker 5 and put it back with the rest of the beakers

Day 4

  1. To measure the final acidity repeat steps 6-9 using a dry pH strip with beaker 1, 2, 3, 4 & 5.

End of Experiment

 Materials:

  • Distilled water
  • 5 Beakers
  • Dropper
  • Straw 
  • 125 pH strips
  • Plate
  • Recording sheet
  • Pencil
  • SodaStream

 

Observations

Observations

  • Observation #1: When I added CO2 to all the beakers, the acidity increased.
  • Observation #2: I observe that the acidity levels changed between days two and three in two circumstances. In the first change, beaker two ended day two at an acidity level of four and started day three with an acidity level of six. In the second change, beaker four ended day two with a five and started day three with a six. For days one and two beaker three changed from a four at the end of day one to five at the start of day two. There were two changes between the days three and four. The first one is beaker four ended day three with a five and started day four with a six. The second one is beaker five tested at acidity level five and tested day four a six.
  • Observation #3: Beaker three, which used the SodaStream maker, became more acidic than the ones I blew into.
  • Observation #4: On day three, beaker two fluctuated many times between acidic level five and acidic level six.
  • Observation #5: During the experiment none of the water tested with an alkaline measurement.

Analysis

Results: Below are the overall results and conclusions of my experiment:

Over the four days of my experiment, the water in beakers two through five had CO2 forced into them in different ways. I conducted my experiment each day around five o’clock PM. Beaker one was the control and stayed at an acidity level or pH of seven, which is neutral, throughout the experiment. Beakers two through five were filled with distilled water not tap water, this was to ensure there were no other particulates or substances that might interfere with my results. Beaker two received CO2 on days one, two and three as I breathed into the beaker with a straw. Beaker three received CO2 on days 1-3 using a Sodastream Maker. Beaker four received CO2 on days two and three as I breathed into the beaker with a straw. Beaker five received CO2 only on day three and I breathed into the beaker with a straw. On day four, I tested all the beakers, but I did not add any additional CO2. This is to observe whether there were any changes in acidity levels between day three and day four.

Beaker two received CO2 on days one, two, and three. On the first day, the acidity level tested at seven at the beginning and after a hundred twenty seconds of expiration, finally tested at an acidity level of six. On day two, beaker two, started the testing at an acidity level of six and after a hundred twenty seconds of expiration, finally tested at an acidity level of four. Interestingly, it tested at an acidity level of five after one hundred ten seconds and at the very last cycle tested at an acidity level of four. On day three beaker two tested at an acidity level of six at the beginning of the cycle and the end of the cycle, however, the acid level moved down to an acidity level of five during the one hundred twenty seconds of expiration. On day four, beaker two tested at an acidity level of six.

Beaker three received CO2 on days one, two, and three using the SodaStream. On the first day the acidity levels tested at seven at the beginning and after a hundred twenty seconds of exploration, finally tested at an acidity level of four The acidity levels changed to a three during the middle of the cycle. On day two, beaker three started the testing at an acidity level of five and after a hundred twenty seconds of expiration, finally tested at an acidity level of four. On day three, beaker three tested at an acidity level of four, and after a hundred twenty seconds of expiration, maintained an acidity level of four at final testing. It did test at an acidity level of three once near the end. On day four, beaker three tested at an acidity level of four.

Beaker four received CO2 on days two and three. On day two, beaker four tested at an acidity level of seven and after a hundred twenty seconds of expiration, finally tested at an acidity level of five. On day three, beaker four tested at an acidity level of six and after a hundred twenty seconds of expiration, finally tested at an acidity level of five. On day four, beaker four tested at an acidity level of six.

Beaker five received CO2 on day three only. Biker five tested at an acidity level of seven and after a hundred twenty seconds of expiration, finally tested at an acidity level of five.On day four, beaker five tested at an acidity level of six.

 

Conclusion

Conclusion

I was correct in my hypothesis that when carbon dioxide (CO2) is added to water (H2O), then it increases the acidity levels in the water forming  carbonic acid (H2CO3). I discovered that, in some cases, the acidity levels did change from the final acidity test of one day to the first acidity test of the next day. For example in beaker two, the measured acidity level at the end of day one was different from the measured acidity level at the start of day two. 

 

Application

New Research Questions

Other question relating to carbonation are:

  1. How would carbonation change if using soda pop as the liquid instead of water. How would the sugars and other ingredients change the results?
  2. How would carbonation change if using tap water. Do the chemicals in tap water change the carbonation of the water?
  3. How would the results from the carbonation process change if you built and used a homemade carbonation machine?

Sources Of Error

Sources of error:

Additionally the testing strips may not always be accurate because they are old. There is an acidity testing machine that is more accurate and consistent that would improve this experiment in the future.

This experiment might be improved by adding more beakers and increasing the length of time. This way the experiment would produce more data therefore more consistent results.

The brands of the distilled water may be different from other distilled water used in a lab. This water was bought at a grocery store.

 

Citations

  1. Can Sparkling Water Replace Regular Water? | Katie McCallum Oct. 2, 2019 https://www.houstonmethodist.org/blog/articles/2019/oct/can-sparkling-water-replace-regular-water/
  2. How Is Water Carbonated? Everything You Need to Know | SodaStream (n.d.) https://sodastream.com/blogs/sodastreams-sparkling-blog/how-is-water-carbonated
  3. The Oxygen Machine | The Science Netlinks. (n.d.) http://sciencenetlinks.com/lessons/oxygen-machine/
  4. Water | National Centre for Biotechnology Information (n.d.) https://pubchem.ncbi.nlm.nih.gov/compound/Water
  5. The Effect of Dissolved Carbon Dioxide on the pH of Water Biology | Harding, T. (2015) https://youtu.be/9nR3vkNRLDg
  6. Why does soda water taste slightly sour when carbon dioxide is odorless and flavorless? | Tyagi A.(2018) https://www.quora.com/Why-does-soda-water-taste-slightly-sour-when-carbon-dioxide-is-odorless-and-flavorless
  7. How Is Water Carbonated? Everything You Need to Know | SodaStream (n.d.) https://sodastream.com/blogs/sodastreams-sparkling-blog/how-is-water-carbonated
  8. Can Sparkling Water Replace Regular Water? | McCallum K. (2019) https://www.houstonmethodist.org/blog/articles/2019/oct/can-sparkling-water-replace-regular-water/

Acknowledgement

I would like to thank the following people:

Thank you to my mom for making all of this happen, supporting me, and analyzing my work and improving it. Thank you to my dad for not always talking about science fair, letting my mind take a break, but still reminding me I have work to do. Thank you to my papa for supplying the materials, showing me how to use them, and always making sure I am doing ok. Thank you to my family for supporting me and giving me a break when I needed it. Thank you to my friends for giving me thumbs up and a reassuring smile while I was presenting