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. 150
C. 50
D. 60

Answer

A

Explanation

`k=(k_1k_3)/k_3`
`Ae^(-E//RT)=(Ae^(-E_(1//RT))Ae^(-E_2//RT))/(Ae^(-E_3//RT))`
or `e^(-E//RT)=e^((-E_(1)-E_(2)+E_(3))//RT)`
or `-E/(RT)=(-E_1-E_2+E_3)/(RT)`
or `E=E_1+E_2-E_2=40+50-60`
`=30" kJ mol"^-1`