Homework 7

Due Thursday, Apr. 18, 2019 at 3:15 p.m. EDT

1. Predict the spin-only magnetic moment (in units of Bohr-Magnetons) for the following complexes:

a. fac-[Co(NH3)3Cl3]

b. trans-[Cr(ox)2Br2]4–

c. trans-[Cr(en)2(CN)2]

2. The rate data shown below was found for the reaction:

[Co(NH3)5X]2+ + OH → [Co(NH3)5OH]2+ + X

What is the order of the reaction? Is this enough information to determine the mechanism of the reaction? If so, what is the mechanism? If not, does it limit the mechanistic options (give the possibilities if this is the case)? What drives the trend in the rate constants? Does this help determine the mechanism? Why or why not?

X

k (M–1s–1)

F

0.012

Cl

0.85

Br

7.5

I

23

3. The rate data shown below was found for the reaction:

[Co(NH3)5X]2+ + [Cr(H2O)6]2+ → Co2+ + 5 NH3 + [Cr(H2O)5X]2+ + H2O

What is the order of the reaction? Is this enough information to determine the mechanism of the reaction? If so, what is the mechanism? If not, does it limit the mechanistic options (give the possibilities if this is the case)? What drives the trend in the rate constants? Does this help determine the mechanism? Why or why not?

X

k (M–1s–1)

F

2.5×105

Cl

6.0×105

Br

1.4×106

I

3.0×106

 

 

Answers