Chemical Kinetics - Result Question 5
####5. The rate constant of the reaction $A \to B$ is $0.6 \times 10^{-3}$ mole per second. If the concentration of $A$ is $5 M$ then concentration of $B$ after 20 minutes is :
[2015 RS]
(a) $1.08 M$
(b) $3.60 M$
(c) $0.36 M$
(d) $0.72 M$
Show Answer
Solution:
- (d) Rate constant $k=0.6 \times 10^{-3}$ mole per second. (unit mole per second shows zero order reaction) For a zero order reaction
$ \begin{aligned} & {[A]=[A]_0-k t} \\ & \text{ and }[A_0]-[A]=[B]=k t \\ & =0.6 \times 10^{-3} \times 20 \times 60=0.72 M \end{aligned} $
