[Sis290025]

A three-step mechanism has been suggested for the formation of carbonyl chloride:

Cl -> 2Cl
Cl + CO -> COCl
COCl + Cl2 -> COCl2 + Cl
 
Which species is an intermediate in the mechanism?
 
 
a.   Cl  
 
b.   CO  
 
c.   COCl  
 
d.   COCl2  

Correct?

The rate constant, k, for a first-order reaction is equal to 4.2 x 10-4 s-1. What is the half-life for the reaction?
 
 
a.   2.9 x 10^-4 s  
 
b.   1.2 x 10^3 s  
 
c.   1.7 x 10^3 s  
 
d.   2.4 x 10^3 s  

ln 2 / (4.2 x 10-4 s-1) = 1.7 x 10^3 s

Thanks.