Why Do Carbonated Sodas Go Flat?
Grade Level: 4th - 5th; Type: Physical Science
What is the project about?
In this science fair project the affect of temperature on the rate of a dissolved gas (carbon dioxide) being released from a club soda solution will be investigated.
What are the goals?
When gas bubbles rise to the surface of a liquid and "pop," the gas goes into the air above the liquid. So, watching bubbles rise to the surface and pop will be used to give a sense of how much gas is being released from the solution. In this project a comparison will be made of the amount of CO2 gas that leaves club soda at cold, room, and warm temperatures by observing the number of bubbles that rise from each. Based on the results of this investigation a data table will be prepared and the results potted on a graph. A practical benefit gained from conducting this project is that the young investigator will be to answer the question of "why carbonated beverages go flat" when they are not stored in the refrigerator.
- Which soda sample has the lowest temperature?
- Which soda sample had the highest temperature?
- Which soda sample had the most "fizz"?
- Which soda sample had the least fizz?
- What happens to the solubility of carbon dioxide gas as the temperature increases?
- Is the solubility of carbon dioxide gas greater at higher temperatures or at lower temperatures?
- When does more gas stay dissolved, at higher temperatures or at lower temperatures?
- Why do carbonated beverages go "flat" when they are not stored in the refrigerator?
The solubility of a gas in a liquid depends on pressure and temperature. As the temperature increases, the solubility of a gas decreases. In general, a change in temperature affects the solubility of gases differently than it does the solubility of solids in liquids, because with relatively few exceptions, the solubility of solids in liquids increases with an increase in temperature.
Carbonated drinks are made by dissolving gases, such as carbon dioxide, into a liquid such as water or corn syrup. When a gas contacts a liquid it naturally dissolves into the liquid until it becomes saturated (can't hold any more). The gas will continue to dissolve into the liquid until the pressure in the liquid is equal to the pressure that pushes down on the liquid. In order to dissolve more gas into the liquid, the gas must be placed under additional pressure.
The "bobbles" or "effervescence" in carbonated soda is caused by carbon dioxide gas dissolved in the liquid. The carbon dioxide gas bubbles provide the pleasant sparkle in the soda and other carbonated beverages. In this science fair activity a comparison will be made of the amount of gas that leaves a carbonated soda sample at different temperatures by observing the number of bubbles that rise from each.
Any required diagrams/pictures (Pictures speak a thousand words!)
Digital photos can be taken during the investigation process also the following sites offer down loadable images that can be used on the display board: