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

`k=(k_(1)k_(2))/(k_(3))`
`Ae^(-E_(a)//RT)=(Ae^(-E_(a_(1))//RT)xxAe^(-E_(a_(2))//RT))/(Ae^(-E_(a_(3))//RT))`
`e^(-E_(a)//RT)=e^((E_(a_(1))-E_(a_(2))+E_(a_(1)))//RT)`
`E_(a)=E_(a_(1))+E_(a_(2))-E_(a_(3))`
`=40+50-60=30 kJ "mol"^(-1)`