Question

Which of the following graphs represent exothermic reaction?

• A. (I) only
• B. (II) only
• C. (III) only
• D. (I) and (II)

Answer 1

Answer: (A)

(I) only

Answer 2

For exothermic reaction, $\Delta H = - ve$

$\Delta H = E_{a(forwardreaction)} - E_{a(backwardreaction)}$ for $\Delta H$ to be $- ve,E_{a,b} > E_{a,f}$ which is true in graph (I) only.