Name:___________________________Per. _____ Date:_____ Integrated Science 7
Alkaseltzer lab report example
Question/Problem: Which Factor affects the speed of the reaction the most?
Hypothesis: If I increase the amount of Alka-Seltzer, then the reaction will go faster
Variables and Controls: My independent variable is the amount of Alka-Seltzer. My
dependent variable is the time it takes the lid to pop off, and my control variables are the
size of container, the amount of water, the temperature of the water, and the shaking. I
will control these variables by always using 15 mL of water, the same container, 24 degrees
Celsius water, and not shaking the film canister.
Materials:
Alka-Seltzer, graduated cylinder, water, thermometer, goggles, film canister, stopwatch
Procedure:
1. Put on safety goggles and gather materials
2. For trial 1, use 1 tablet Alka-Seltzer ; use 2 tablets for trial 2; use 3 tablets for
trial 3, use ½ a tablet for trial 4
3. Put tablet on lid of film canister, and add 15 mL of 24 degrees Celsius water to the
canister.
4. Have your partner start the stop watch when you shut the lid and stop it when the
lid pops off.
5. Yell “fire in the hole” when you quickly drop the Alka-Seltzer in the canister and
snap the lid on, and hold the canister away from your body.
6. Record the time it takes for the lid to pop off.
Data and Observations:
My Group’s Data Table
Trial
Amount of
Alka-Seltzer
Amount of
water
Trial 1
1 tablet
Trial 2
Trial 3
Trial 4
2 tablets
3 tablets
1/2 tablet
Shaking or
not
Time lid
pops off
15 mL
Temperature
Degrees
Celsius
24
Don’t shake
10 seconds
15 mL
15 mL
15 mL
24
24
24
Don’t shake
Don’t shake
Don’t shake
6 seconds
2 seconds
13 seconds
Class Comparison of Fastest times
Variable value
3 tablets
46 degrees celcius
Fast shaking
10 pieces
25 mL
The Effect of Amount of
Alka-Seltzer on the Speed
Fastest time
2 seconds
3.46 seconds
6.71 seconds
7 seconds
5.23 seconds
The Fastest Times Measured for Each
Variable
I observed during our experiment that as I increased the amount of Alka-Seltzer, the
time it took for the lid decreased a lot. The one that popped off the fastest was the trial
with 4 Alka-Seltzer tablets. I saw bubbles and foam forming inside the canister during
the experiment.
Inferences: I think that increasing the amount of Alka-Seltzer makes the reaction go
faster. I think that a gas is being released by the Alka-Seltzer, and so adding more AlkaSeltzer means that more gas is being formed at the same time, so it takes less time for
enough pressure to build and make the lid pop off.
Evidence: I observed bubbles being formed, and the lid pops off, so a gas is being
released. The reaction took the longest (13 seconds) when there was the least amount of
Alka-Seltzer (1/2 tablet). The reaction was the shortest (3 seconds) when there was the
biggest amount of Alka-Seltzer (3 tablets).
Conclusion:I have accepted my hypothesis because the reaction took less time (3 seconds)
when there was more Alka-Seltzer (3 tablets). So increasing the amount of Alka-Seltzer
does increase the speed of the reaction. When I compared my data to the rest of the
class, nobody else was able to get their lids to pop off in less than 1 second, so I think that
the amount of Alka-Seltzer is the most important factor in how fast this reaction goes.
My ideas have changed because I figured adding more Alka-Seltzer would make the
reaction go faster, but I didn’t know that the amount of Alka-Seltzer was the most
important factor out of the five we talked about.