Chem 334 - Summer 1998 - Organic Chemistry I Dr. Carl C. Wamser

Chapter 3 Quiz

1. (2 pts) Use the attached table of bond dissociation energies to calculate deltaH for the following hypothetical reaction:

CH3CH2CH3 + F2 -----> CH3F + CH3CH2F

bonds broken: CH3CH2-CH3 (86) and F-F (37)

bonds made: CH3-F (110) and CH3CH2-F (107)

delta H = 86 + 37 - 110 - 107 = - 94

2. (4 pts) Use the selectivity data table to calculate the relative amounts of all possible monochlorination products expected from chlorination of 3-ethylpentane.

3. (4 pts) One propagation step is shown below. Add another propagation step that would create a chain reaction and show what the overall reaction would be.

H + Cl2 -----> HCl + Cl

Cl + H-Z ---> Z-Cl + H (second propagation step)

HZ + Cl2 ---> HCl + ZCl (overall reaction)

(lots of hypothetical possibilities for Z)