For a reaction taking place in three steps, the rate consatnt are `k_(1),k_(2) and k_(3)`. The oveall constant `k=(k_(1)k_(2))/(k_(3)` . If the energy of activation values of for the first, second and third stage are 40,50 and 60 kJ `"mol"^(-1)` is :

Options

A. 30
B. 40
C. 60
D. 50

Answer

A

Explanation

Overall rate constant `k=(k_(1)k_(3))/(k_(2))`
`k=Ae^(-E_(a)//RT)`
`:.k=(k_(1)k_(2))/(k_(3))=Ae^(-(E_(a_(1))+E_(a_(2))-E_(a_(3)))//RT)`
`=Ae^(-(40+50-60)//RT)`
`=Ae^(-30//RT)`
`E_(a)=30kJmol^(-1)`