An exothermic chemical reaction proceeds by two stages reactants `overset("Stage I")(rarr) "intermdediate" overset("Stage II")(rarr)` products, The activation energy of stage `I` is `50 kJ mol^(-1)`. The overall enthalpy change of the reaction is `-100 "kJ mol"^(-1)`. Which diagram could represent the energy level diagram for the reaction ?

Options

A.
B.
C.
D.

Answer

C

Explanation

It is an exothermic reaction `(Delta H lt 0)`, with the formation of an intermediate. Thus internal energy of P is less than R (as reaction is exothermic) and there are two peaks (indicating formation of an intermediate) with `E_(act)` for state `I = 50 "kJ mol"^(-1)`. This is correct for choice (C) only.