Half life of zero order reaction A product is 1 hour, when initial concentration of reactant is 2.0 mol L-1. The time required to decrease concentration of A from 0.50 to 0.25 mol L-1 is :
- 0.5 hour
- 15 min
- 60 min
- 4 hour
Answer
(2) 15 min
Solution
For a zero order reaction: t1/2 = [A]02k
k = [A]02 t1/2 = 2.02 1 = 1.0 mol L-1 h-1
Integrated rate law: [A]0 - [A] = kt
t = 0.50 - 0.251.0 = 0.25 h
= 0.25 60 min = 15 min
Answer: (2)