chemistry

Write the appropriate equation/s you would need to solve each of the following problems:

Problem Equation + notes on what you need to watch out for

in each problem!

1. A reaction has a rate constant of 0.0117 /s at

400.0 K at 0.689 /s at 450.0 K. Determine the

activation energy of the reaction.

(Ea in J/mol!, T in K, keep track of indices, -ive sign)

2. If a reaction, A -> products, has a rate constant of

0.450 M -1

s -1

, and the initial concentration of A is

0.85 M, what will the concentration of A be after 25

minutes?

3. What is the initial rate of a reaction A -> B that is

first order in A and has a starting concentration of

0.54M and a rate constant of 0.210 s -1

.

4. For the reaction H2 + I2 -> 2HI, if the rate of

formation of HI is 0.023M/s, what is the rate of

disappearance of H2 at the same instant?

5. The half life of a second order reaction A->

products is 36 minutes. Calculate the rate constant

given that the initial concentration of A is 0.123M.

6. The slope of a graph of ln[A] versus time is

-0.004 s -1

. What is the rate constant for this reaction?

7. Determine the frequency factor for a reaction with

a rate constant of 0.0218 s-1 at 298K and an

activation energy of 52 kJ/mol.

8. Fluorine-18 decays a first order process, and has a

half life of 1.83 hours. If 1.3 x 1015 atoms of

fluorine-18 were administered to a patient during a

Positron Emission Tomography scan, how many

atoms would remain after 24 hours?

9. What is the rate law of an elementary reaction

that is believed to proceed by the following

mechanism: A + A -> B

10. The mechanism of a reaction is shown below.

HOOH + I ¯  HOI + OH

¯ (slow)

HOI + I ¯  I2 + OH

¯ (fast)

2OH ¯ + 2H3O

+  4 H2O (fast)

Predict the rate law based on this mechanism.

11. The mechanism of a reaction is shown below.

HOOH + I ¯  HOI + OH

¯ (fast)

HOI + I ¯  I2 + OH

¯ (slow)

2OH ¯ + 2H3O

+  4 H2O (fast)

Predict the rate law based on this mechanism.

Don’t try to solve this one!

12. Determine the equilibrium concentration for HBr

for the following reaction. The equilibrium

concentrations are: [H2] = 0.10 M, [Br2] = 0.12 M.

Reaction has a Kc of 0.30.

+

13. Calculate for the following reaction given the value.

14. A 3.00 L container currently has 0.010 mol and 0.0080 mol at 298 K. What is and which way will the reaction shift?

15. The rate constant for a particular reaction is

. If you start with 5.0 M of reactant, how much reactant should be left after 2 min?

16. Write a balanced reaction for which the following

rate relationships are true.

17. What rate law is implied by the experimental data

given below?

Exp. 1 0.100 0.100 0.050

2 0.200 0.100 0.100

3 0.200 0.200 0.400

18. A second order reaction has a rate constant of 2.0

. Find the concentration of the starting material after 5 minutes, given the initial concentration ?

19. Consider the following chemical reaction at a

certain temperature.

Initially, only and were present in the reaction container. Once equilibrium is

reached, the concentration of is found to be 0.015 M.

20. Consider the chemical reaction at :

If a reaction mixture initially contains 0.200 M and no other substances, find the equilibrium

concentration of . If you use the small x approximation, justify it.

21. The solid line below represents the concentration

of A over time for a simple decomposition reaction.

Calculate the instantaneous rate of disappearance of

A at 50 seconds. The dashed lines may or may not

be useful in this calculation.