We are proving that “concentration” (the amount of reactants) is one of the things that can affect the speed of chemical reactions. We are also finding a way to keep the lid on the film canister for the longest period of time. We are using vinegar and water as reactants and changing the concentration every time to see the difference between the rates of reactions speed.
- 1 graduated cylinder
- 1 film canister
- Phone (as timer)
- 2 Alka-Seltzer tablets
- Electronic scale
1. Fill the graduated cylinder with 10ml of vinegar and put it in the clean film canister.
2. Break the Alka-Seltzer tablets to two parts from the middle, measure both parts on the electronic scale (half tablet is 1.5g) and break little pieces from the bigger half if necessary, to make both parts weight as close as possible.
3. One person set the timer while the other person put half of the tablet into the film canister and close the lid.
4. Wait for lid to pop off and record the time.
5. Wash the graduated cylinder and the film canister.
6. Refill the cylinder with 5ml of water and 5ml of vinegar.
7. Use the other half of tablet and repeat step 3-5.
8. Refill the cylinder with 10ml of water only and repeat step 2-4.(Use tablet#2)
9. Refill the cylinder with 10ml of vinegar only and use the other half of tablet#2.
10. Clean up.
The independent viable is the concentration of reactants (we are changing the concentration of vinegar by adding water) to see how it affects the speed of chemical reactions. And the dependent viable is the speed of reactants (how long does it take to pop the lid every times). The constants are the same room temperature, same film canister and same amount of Alka-Seltzer tablet.
Amount of Vinegar
Amount of Water
Concentration of vinegar