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
The activation eneries for forward and backward reactions in a chemical reaction are `30.5` and `45.4 kJ mol^(-1)` respectively. The reaction is

Options

A. Exothermic
B. Endothermic
C. Neither exothermic nor endothermic
D. Independent of temperature

Answer

A

Explanation

`Delta H = E_(f)-E_(b) = 30.5-45.4 = -14.9 kJ mol^(-1)`
i.e., reaction is expthermic because heat is evolved during the reaction.