6.05 Rate and Collision Theory

6.05 Rate and Collision Theory Does surface area affect dissolving of Alka-Seltzer tablets?
Materials:
1. solo cups
2. Alka-Seltzer tablets
3. Timer
4. Measuring Cup
5. Thermometer
Procedures:
1. I placed out two of my solo cups on the counter
2. Then I put 1 cup of room temperature water into each cup.
3. Then put one Alka-Seltzer Tablet in one cup and time it until it dissolves completely.
4. In the second cup I put in a crushed up Alka- Seltzer tablet and timed it until it dissolved.
5. Repeat steps 1 through 4 one more time.

Crushed Alka-Seltzer
21.86 seconds
23.52 seconds
Whole Alka-Seltzer
29.15 seconds
35.33 seconds

Discussion and Conclusion:
Answer the following questions in complete sentences.
1. What two factors did you investigate in your procedure, and why did you choose to compare these two factors? The two factors I investigated were surface area and Alka-Seltzer. I decided to pick those if the surface area made the Alka-seltzer dissolves faster.

2. What other factors did you need to control during your investigation? Explain how you controlled each one in your procedure. Factors that I needed to control in my experiment was the temperature of water, how many Alka-Seltzer tablets to put in, and how much water to use in the cups. I had a thermometer to make sure that when I done my two trials that they both had the same temperature of water, I only put one tablet per cup, and I made sure to have the same amount of water in each cup I used.

3. What was your prediction about the results of each factor tested in your two lab procedures? Explain your predictions based on your knowledge of the dissolving process, collision theory, and reaction rates. My predictions of the results on this lab were right. I figured that if the Alka-Seltzer were crushed up it would make it more easier to dissolve since they were in little pieces instead of one big tablet.

4. In your own words, explain the collision theory, and what is necessary for a collision to be successful? Collision theory is a theory that when molecules collide in a certain way with the certain amount of energy they start to form new substances.

5. A specific catalyst was not provided for this reaction, but catalysts are useful for increasing the rate of many slow reactions. In your own words, give a detailed explanation of how catalysts can increase the rate of a reaction or process? Catalysts can increase the rate of a reaction or process because they help speed things up by reducing the amount of energy required for the reaction to happen.