The purpose of this experiment was to determine if changing the form of Alka-Seltzer when added to the water, affects the time it takes for the cap to burst.
Alka-Seltzer is a remedy for indigestion that is dissolved in water and ingested by mouth. The active ingredient is sodium bicarbonate, which is baking soda. Alka-Seltzer reacts with water to produce carbon dioxide gas. In an enclosed space, like a film canister, the pressure of the gas increases until the film canister’s lid pops off, and the lid flies into the air.
The purpose of this experiment was to examine changes in the dependent variable (the time until burst) as we changed the independent variable (the form of Alka-Seltzer).
The hypothesis was that if the form of the Alka-Seltzer (the independent variable) is changed to increase the surface area initially coming in contact with the water speeding the creation of carbon dioxide gas, then the time until the cap burst (the dependent variable) would decrease.
The following items were used in the experiment:
- Graduated cylinder - used to measure water
- Film canister (lid and tube) – container for water, Alka-Seltzer, and carbon dioxide gas
- 120ml of room temperature water – 10ml added to each tablet
- 12 Alka-Seltzer tablets – One tablet used per test
Step 1: To keep each test reasonably the same, the same amount of water was used in each test. 10ml of room temperature water (always the same temp.) was put into the film canister.
Step 2: One of the remaining four forms of Alka-Seltzer (1 whole tablet, 2 half tablets, 4 quarter tablets, or one powdered tablet) was added to the water.
Step 3: The cap was then sealed onto the canister. At nearly the same moment, a stopwatch was started.
Step 4: The stopwatch was stopped at nearly the moment the cap burst of the canister.
Step 5: The data of which of the four forms the Alka-Seltzer was in, which number that test was for that...