### All AP Chemistry Resources

## Example Questions

### Example Question #1 : Integrated Rate Laws

The rate constant for a second-order reaction is 0.15 M^{-1}s^{-1}. If the initial concentration of the reactant is 0.30 M, how long does it take for the concentration to decrease to 0.15 M?

**Possible Answers:**

253 second

44.4 second

88.8 seconds

22.2 seconds

11.1 seconds

**Correct answer:**

22.2 seconds

### Example Question #2 : Integrated Rate Laws

Based on the figure above, what is the order of reaction?

**Possible Answers:**

Squared Order

First order

Second Order

Third Order

Zero Order

**Correct answer:**

First order

For a first order reaction, the ln [A]_{t} is linear with t.

### Example Question #1 : Integrated Rate Laws

A compound decomposes by a first-order process. If 25.0% of the compound decomposes in 60 minutes, the half-life of the compound is?

**Possible Answers:**

198 minutes

65 minutes

180 minutes

120 minutes

145 minutes

**Correct answer:**

145 minutes

### Example Question #4 : Integrated Rate Laws

Cyclopentane is unstable and decomposes by a first order reaction. The rate constant for this reaction is 9.5 s^{-1}. What is the half life of the reaction?

**Possible Answers:**

0.132 seconds

0.0729 second

0.0582 seconds

0.0314 seconds

0.0614 seconds

**Correct answer:**

0.0729 second

### Example Question #5 : Integrated Rate Laws

The half life of a first order reaction is 1.5 hours. What is the rate constant of this reaction?

**Possible Answers:**

1.5

0.46

0.21

0.52

0.75

**Correct answer:**

0.46