A colliison between reactant molecules must occur with a certain minimum energy before it is effective in yielding Product molecules. This minimum energy is called activation energy `E_(a)` Large the value of activation energy, smaller the value of rate constant `k`. Larger is the value of activation energy, greater is the effect of temperature rise on rate constant `k`.

`E_(f) =` Activation energy of forward reaction
`E_(b) =` Activation energy of backward reaction
`Delta H = E_(f) - E_(b)`
`E_(f) =` threshold energy
In a hypothetical reaction `A rarr B`, the activation energies for the forward and backward reactions are `15` and `9 kJ mol^(-1)`, respectively. The potential energy of `A` is `10 kJ mol^(-1)`. Which of the following is wrong?

Options

A. The threshold energy of the reaction is `25 kJ`.
B. The potential energy of `B` is `16 kJ`.
C. The heat of reaction is `6 kJ`.
D. The reaction is exothermic.

Answer

D

Explanation

`Delta H = E_(f) -E_(b) = 15-9 = 6 kJ mol^(-1)`, i.e., endothermic.
THE `=E_(a(f)) + PE` of `A = 15 + 10 = 25 kJ`
`PE` of `B = THE-E_(a(b)) = 25-9 = 16 kJ`
So statements (a), (b) and (c ) are correct and (d) is wrong.