The energy change accompanying the equilibrium reaction `A hArr B` is `-33.0 kJ mol^(-1)`.

Assuming that pre-exponential factor is same for forward and backward reaction answer the following:
The threshold energy of the reaction is when `PE` of `B` is `30 kJ mol^(-1)`.
(a)`30`
(b)`140`
(c)`123`
(d) `125`

Options

A. `30`
B. `140`
C. `123`
D. `125`

Answer

C

Explanation

threshold energy
`= E_(b) + PE` of Product
`= 93+30 = 123 kJ mol^(-1)`