Introduction: (Initial Observation)
This project will determine which soft drink among several colas and root beers has the greatest amount of carbonation. First select which soft drinks are to be tested. At least three different soft drinks should be selected as a minimum number, with four or five to be preferred.
Measuring carbonation is important because of the health hazards of excess carbonic acid.
Measuring the amount of carbonation is a task performed in quality control labs and it is helpful for students to be familiar with such procedures. Some students may need to do similar procedures as part of their jobs in future. Comparison of the amount of carbonation is sometimes between different products of the same brand. Conditions such as temperature and concentration of other solutes can affect the amount of carbonation. (Drop a cube sugar in a cup of soda to see how increase in the amount of sugar reduce the amount of carbonation). You may have experienced buying beverages that are relatively flat in the past. That is an indication that not all beverages have the same level of carbonation. For some beverages such as beer, natural carbonation also indicates the rate of fermentation.
For each soft drink brand selected, see if there is a home-page on the web and find any information the producer provides about carbonation in their product. Also search the web for the term “carbonation” and related terms to gain useful information about the carbonation process itself.
Following are samples of information that you can find.
Carbonation is dissolving carbon dioxide in water:
Carbonation is a process, of either injecting or by natural means, where carbon dioxide gas (CO2) is introduced into a liquid creating an effervescence or bubbly texture, adding to the taste and pleasantness of many of the beverages we drink everyday. Soft drink companies alone make billions of dollars producing carbonated products that tingle the taste buds of the consumer, and companies work diligently in keeping these bubbles happy and active. Bakers, as well as beer and wine makers all rely heavily on these tiny little bubbles to enhance the taste, and energize their normally flat and lifeless products. Carbonation can occur in a variety of ways either naturally or artificially, and we will explore the various methods used in carbonating liquids, as well as some of the products where they can be utilized. Some things carbonate themselves, and others need a little help.
Carbon dioxide is a preservative and carbonation is a method used to preserve beverages. Carbon dioxide dissolved in a beverage (or, more specifically, water) forms carbonic acid. This acid is perceived as bitterness in the beverages.
- High carbonation causes an unpalatable bitterness, low body, and a burning sensation on the tongue (as the CO2 bubbles form on your tongue).
- Low carbonation can be perceived as high body, sweet, and flat – no tingle on the tongue due to CO2 bubbles.
Certain conditions allow for carbonation to happen naturally and just as much enjoyed as that of a can of soda. In spring water for example, carbonation takes place at high pressures underground. Limestone or other related calcites such as those found in sedimentary rock, are broken down by carbonic acids, and the reaction between acid and base (limestone) produce a carbon dioxide gas which is compressed (squeezed) into the water. Once the carbonated water reaches the fresh air outside, it wants “out-of-there” and diffuses (mixes) with the air, giving the water it’s sparkle and bubbly effervescence.
Carbonation can also be the byproduct of fermentation such as that found in sparkling wine, beer and champagne. Fermentation begins as yeast or some other mold or bacteria is introduced into the grape (wine), or grain (beer), mixture. The yeast acts as an enzyme breaking down the big sugars (carbohydrates) into little sugars (simple sugar), and in the process produces carbon dioxide gas and alcohol. Once fermentation starts, it’s bottled and corked to keep all the carbon dioxide gas from escaping into the atmosphere. It’s a kind of un-doing what nature put together through photosynthesis, and vintners take special care to control the whole process as it effects the taste and esthetics of a decadent finished product. Sometimes a little more sugar is added, as in the case of champagne, to increase the amount of bubbles and alcohol once the enzymes have broken down all the sugar from the grapes (secondary fermentation).
Our kitchen is another place where we might find carbonation taking place. When yeast or baking powder is combined with a sodium hydrogen carbonate (NaHCo2), commonly known as baking soda, you have the same effect as mixing bases and acids together. Both are very soluble in water once heated above 50 degrees Celsius, and emits a carbon dioxide gas that gives rise to your homemade bread or soufflé.*Just be careful not to slam the oven door!* Seltzer tablets also combine an acid with a base. When diluted in water, the two combine to form carbon dioxide gas: a bubbly characteristic useful for relieving excess gas in your stomach.
Artificial means to carbonate:
Carbonation can also be the result from injecting the carbon dioxide gas directly into a liquid. Artificial carbonation was first introduced by Joseph Priestly (1767), and commercialized by Benjamin Silliman (1807), who bottled it as seltzer water. Later, flavoring was added by innovators such as Hires and Pemberton, who stumbled upon a pleasant tasting soft drink such as cola and root beer, the rest is history.
In order to force-carbonate a liquid, two conditions have to be met; (1) the liquid must be cold enough to accept the carbonation, and (2) the liquid must be in a sealed container to allow for the gas to be pressurized into the mixture.
Carbon dioxide is soluble in a solution in an inverse relationship to the temperature of the liquid that it’s being applied to. The colder the liquid is, the easier carbon dioxide will dissolve into it. The basic rule of thumb is the colder the better because of the ease of solubility between the liquid and carbon dioxide at lower temperatures. The colder the liquid, the more carbon dioxide will be able to dissolve, keeping it into the solution longer rather than escaping and turning the liquid flat. This can be demonstrated by opening a cold can of soda, and then opening a can that’s been sitting in the sun for awhile. The cold can will remain carbonated longer after it’s open, and the warm can will foam right away and lose its fizz shortly afterward as the gas escapes from the can and diffuses into the open air.
(2) Sealing the container:
The gas mechanically injected into the liquid must be pressurized and sealed in order for the liquids to not only absorb the CO2, but to keep it from escaping into the atmosphere. Water and carbon dioxide share a weak bond, and the gas will seek every opportunity to escape leaving your soda flat even in cold temperatures. Agitation also effects the intensity of the carbon dioxide that has been dissolved into the liquid. By shaking a can for example, the sleeping CO2 comes out of hibernation and is exposed to the outside where it can diffuse into the atmosphere. The more carbon dioxide exposed will determine the amount of “fizz” that comes out of the can.
As the result from a little creativity and problem solving, we use carbonation in a variety of different ways besides making great tasting beverages. Below is a list of practical uses and devises where these tiny little bubbles make our life a little easier.
- Fire extinguishers – Certain fire extinguishers contain CO2 gas or dry ice to put out certain types of fires.
- Carpet cleaning – Some commercial carpet cleaners have machines that inject carbon bubbles into carpets that lift out dirt and remove stains.
- Club soda – This seltzer is useful in removing stubborn stains from clothes and fabric.
- Polident – is a product that uses effervescent bubbles to clean food stains off dentures.
- Upset stomach or hangover? – Products like Alka Seltzer neutralize excess acid in the stomach, providing relief from indigestion.
- Baked goods – Carbonation is what give rise to breads, cakes, and pizza dough etc.
- Rain clouds – Research is being done by scientists using a form of carbonation (dry ice) to seed clouds making it rain in strategic places.
- Dairy products – Research is being done to explore the practicality of carbonated dairy products. Carbonation extends the shelf life of whole milk as well as certain cheeses, but taste gets altered in the process and further developments are needed to retain the original taste and texture.
Carbonation in the beverage causes the opening from the stomach to the small intestine to relax, emptying its contents more rapidly. Source…
What do you want to find out? Write a statement that describes what you want to do. Use your observations and questions to write the statement.
The purpose of this project is to identify which soft drink contain most carbon dioxide gas.
When you think you know what variables may be involved, think about ways to change one at a time. If you change more than one at a time, you will not know what variable is causing your observation. Sometimes variables are linked and work together to cause something. At first, try to choose variables that you think act independently of each other.
- The independent variable is the type of soft drink.
- The dependent variable is the amount of gas in each soft drink.
- Controlled variable is the temperature
- Constants are the size and packaging of the soft drink as well as the experiment method and procedures.
Based on your gathered information, make an educated guess about what types of things affect the system you are working with. Identifying variables is necessary before you can make a hypothesis.
The student will state which soft drinks have been selected and then the hypothesis will state which of the soft drinks is believed to have the greatest amount of carbonation. The hypothesis may be based on the student’s intuition or past experiences with the soft drinks.
This is a sample hypothesis:
I hypothesize that sprite has the highest carbonation. My hypothesis is based on my experience from the acidic taste of sprite.
Design an experiment to test each hypothesis. Make a step-by-step list of what you will do to answer each question. This list is called an experimental procedure. For an experiment to give answers you can trust, it must have a “control.” A control is an additional experimental trial or run. It is a separate experiment, done exactly like the others. The only difference is that no experimental variables are changed. A control is a neutral “reference point” for comparison that allows you to see what changing a variable does by comparing it to not changing anything. Dependable controls are sometimes very hard to develop. They can be the hardest part of a project. Without a control you cannot be sure that changing the variable causes your observations. A series of experiments that includes a control is called a “controlled experiment.”
The Materials Needed
Materials Needed are:
1. Three small bottles of each soft drink selected. All bottles should be the same size (by
weight). Using different sized bottles would invalidate the project.
2. A supply of small, round party balloons, one for each bottle to be tested.
3. A supply of small rubber bands to secure the balloons to the bottle tops.
4. A cloth measuring tape such as a seamstress might use
5. The project book or other writing implements to record experimental results
Cool all soft drinks in the refrigerator. Plan to test each brand of soft drink individually. Remove the three bottles of brand #1 from the refrigerator being careful to not shake or disturb them more than necessary. Place them on the counter top and remove the caps one at a time. As soon as the cap is off, place a balloon over the bottle top and secure it in place with a rubber band. The lip of the balloon, and the rubber bands, should be BELOW the threads on the bottle. When all three bottles are covered with balloons and secured, the experiment begins. CAUTION: If the balloons are not well secured there can be a mess to clean up
Take a single bottle in hand, placing a thumb securely over the top of the bottle in such a way that the soft drink cannot enter the balloon immediately, and shake the bottle vigorously. As ALL bottles will have to be treated as nearly the same as possible, we recommend a counted number of shakes, perhaps 6 or 7, then remove the thumb so that the escaping carbonation (CO2) will rush into the balloon. Some of the soft drink will also spray into the balloon but it will drain back into the bottle while the gases will inflate and remain in the balloon.
Now wait for a period of time for additional gases to escape from the soft drink and fill the balloon. Wait at least 45 seconds but more than 60 is probably not needed. Whatever time period is chosen, it should be kept the same for all bottles tested.
At the end of the waiting period, the flexible tape measure is used to measure the circumference around the balloon and its widest part. Carefully measure and record this data.
Next proceed to shaking the second of the three test bottles.
Measure the gas volume:
When all three test bottles for one soft drink have been shaken, the carbonic gas from the soft drinks will inflate the balloons. The volume of the released gas is the same as the volume of the balloons. To measure the volume of the balloons, first measure the circumference of each balloon. Find out how you can measure the volume of a sphere (see the calculation section) and calculate the volume of each balloon. Then take the average of the three measurements and use it as the gas volume for that specific soft drink brand.
Based in the volume of the soft drink in your bottle, calculate the amount of gas produced from one liter of each soft drink.
Then repeat the above procedures for each of the remaining soft drink brands in the test.
Your results table may look like this:
|Soft Drink name/ brand||Amount of CO2 per liter*|
|Soft Drink #3|
|Soft Drink #4|
Draw a graph:
Make a bar graph with one vertical bar for each soft drink that you test. The height of each bar will show the amount of gas per liter. Under each bar write the name of each soft drink that it represents. On the top of the bar write the amount of gas in mL (Cubic Centimeters).
* See the calculations section to learn how you can calculate the volume of the CO2 gas.
Need a control experiment? Place another balloon on the top of an empty bottle and do nothing with that. The purpose of having a control experiment is to show that the balloons are not inflated by an unknown and unrelated environmental factor, and in fact the gas in balloons is coming from the soft drinks.
Results of Experiment (Observation):
The data could be presented in written form or a bar graph would be an excellent visual method of displaying the final results. Each brand tested should have its own bar. The length of the bars would be proportional to the circumference measured.
Measure the circumference of the balloon.
Calculate the radius of a spherical balloon by dividing the circumference of the balloon by 6.28.
Calculate the volume of the balloon using the formula volume=4/3¶r3
In the above formula r is the radius, r3 means r x r x r, and ¶ = 3.14
To calculate the volume of the balloon multiply 4/3 x 3.14 x radius x radius x radius. For example if the circumference of a balloon is 32 inches, you divide 32 by 6.28 to get 5 as the radius of the spherical balloon. Then the volume will be 4/3 x 3.14 x 5 x 5 x 5 = 523 cubic inches.
Write the volume of the balloon in the “CO2 amount” column of your results table.
If r or radius is in inches, the volume will be in cubic inches. If r is in centimeters, the volume will be in cubic centimeters.
Summary of Results:
All measurements should be recorded in the project book and may be presented in the final project report either as numerical data or shown as a bar graph. For each brand of soft drink tested, the length of the bar should show the average circumference of the balloon. Note that the “actual” amount of carbonation has not been measured but only the relative amounts of carbonation compared to the other soft drinks in the test.
The conclusion to the report will state the ranking of the various soft drinks, and decide if the original hypothesis was proven or disproved. The conclusions might also state any relationships the student has noted between the popularity of a given soft drink and the amount of carbonation it contains, as well as any factors noted during the project which might lead to future projects about carbonation.
Related Questions & Answers:
What you have learned may allow you to answer other questions. Many questions are related. Several new questions may have occurred to you while doing experiments. You may now be able to understand or verify things that you discovered when gathering information for the project. Questions lead to more questions, which lead to additional hypothesis that need to be tested.
If you did not observe anything different than what happened with your control, the variable you changed may not affect the system you are investigating. If you did not observe a consistent, reproducible trend in your series of experimental runs there may be experimental errors affecting your results. The first thing to check is how you are making your measurements. Is the measurement method questionable or unreliable? Maybe you are reading a scale incorrectly, or maybe the measuring instrument is working erratically.
If you determine that experimental errors are influencing your results, carefully rethink the design of your experiments. Review each step of the procedure to find sources of potential errors. If possible, have a scientist review the procedure with you. Sometimes the designer of an experiment can miss the obvious.
List your References here. Following is a sample:
- “Carbon Dioxide,” Handbook of Compressed Gases, 3d ed., Compressed Gas Association, Inc., New York, 1990, pp. 284-300.
- Chopey, Nicholas P., with Cathy Cooper, Charlene Crabb and Gerald Ondrey, “Technology to Cool Down Global Warming,” Chemical Engineering, January 1999, pp. 37-41.
- McCoy, Michael, “Industry Intrigued by CO2 as Solvent,” Chemical and Engineering News, June 14, 1999, pp. 11-13.
- “Production and Market of Carbon Dioxide,” China Chemical Reporter, March 30, 1999.