factors effecting reaction rates (chem lab)

Effects of Particle Size, Temperature, Concentration, and a Catalyst on Reaction Rate

Introduction: Chemical reactions can be affected by a number of different factors. Particle size, temperature, concentration of a solution, and catalysts play a big role in the rate of reaction, they determine how fast a reaction will occur. According to the collision theory, the rate of reaction depends on the frequency of effective collisions between particles. Every reaction is different in that they all require different conditions and factors in order to have the most effective collisions. However, the one thing that remains the same for every reaction is that the more effective collisions there are, the faster the reaction occurs. In this experiment, particle size, temperature, concentration of a solution, and catalysts will be tested to determine how they influence the rate of reaction.
Materials:

1. Goggles
2. Powdered calcium carbonate (CaCO3)
3. Metal scoop
4. Marble chips
5. Cold water
6. Hot water
7. Room temperature water
8. 1M hydrochloric acid (HCl)
9. 3 M HCl
10. Iron (III) chloride (FeCl3)
11. Sodium chloride (NaCl)
12. Calcium chloride (CaCl2)
13. Potassium nitrate (KNO3)
14. 0.3% hydrogen peroxide (H2O2) solution
15. 8 test tubes
16. Test tube rack
17. 3 250mL beakers
18. Alka Seltzer tablet
19. 3 pieces of zinc metal

Procedure: Particle size
1. Have two test tubes in the test tube rack. Put 1M hydrochloric acid into both of these test tubes.
2. Take a scoop full of powdered CaCO3 and put it in a test tube at the same time you put a marble chip into the other test tube.
3. Note the reaction rate of each and record it in the table.
Procedure: Temperature
1. Fill each beaker half way. One with cold water, one with hot water, and the last with room temperature water.
2. Take the pieces of alka seltzer and put them in each beaker one at a time so you can time each reaction.
3. Record the reaction rates in the table.
Procedure: Concentration
1. Set up 2 test tubes in the test tube rack and put about 5mL of 1M hydrochloric acid in one and 3M hydrochloric acid in the other.
2. Drop a piece of Zn into one of the test tubes and time how long the reaction takes.
3. Repeat step 2 for the other test tube.
4. Record how fast each reaction occurred.
Procedure: Catalyst
1. Set up 4 test tubes in the test tube rack with 5mL of 0.3% H2O2 solution each.
2. Add 5 drops of the following catalysts to different test tubes:
a. FeCl3
b. NaCl
c. CaCl2
d. KNO3
3. Record the reactions in the table.
Results:
Particle Size
Substance Tested
Observations
CaCO3
Reacted quickly; more surface area is exposed
Marble chips
Reacted quickly as well, but not as fast.

Temperature
Water Condition
Temperature
Time to Completion
Cold
(40°F - 32) ×5/9 = 4.4°C
3m 1s
Room Temperature
(65°F - 32) ×5/9 = 18.3°C
1m 2s
Warm
(180°F - 32) ×5/9 = 82.2°C
10s

Concentration
Concentration
Reaction Time
Observations
1M
4m 19s
Reacted slowly
3M
1m 49s
Reacted quickly

Catalyst
Possible Catalyst
FeCl3
NaCl
CaCl2
KNO3
Reaction Rate
All the catalysts had the same reaction, they started to bubble slowly.

Conclusion: In conclusion, I was able to see the effect of different conditions on the rate of reaction. For the particle size test, I observed that the powdered CaCO3 reacted faster with the hydrochloric acid that the marble chips. This is because more surface area was exposed and more of the CaCO3 was able to react with the hydrochloric acid than the marble chips. The temperature test was also successful because as soon as I dropped the alka seltzer tablet into the hot water, almost all of it dissolved right away. However, when it was dropped into the cold water, it took 3 minutes to dissolve. The concentration test showed that the higher the concentration, the faster the reaction occurred. When the zinc was placed in the 1M hydrochloric acid, it took 4 minutes to react. When the zinc was placed in the 3M hydrochloric acid, it only took 1 minute to react. The catalyst test was inconclusive. Every catalyst behaved the same way, they all bubbled with the 0.3% hydrogen peroxide solution. To make this test better, we could have increased the concentration of the hydrogen peroxide solution or maybe given the catalysts more time.