Question

Activation energy of forward and backward process of the reaction are $60$ $kJ$ and $40$ $kJ$ ${mol}^{-1}$ respectively. Which of the following are true for the reaction?

• A. It is an endothermic reaction.
• B. It is an exothermic reaction.
• C. Heat of reaction is $+20kJ{mol}^{-1}$.
• D. Threshold energy of reaction can be $100$ $kJ$ ${mol}^{-1}$.

Answer 1

Answer: (A), (C), (D)

The correct options are
A It is an endothermic reaction.
C Heat of reaction is $+20kJ{mol}^{-1}$.
D Threshold energy of reaction can be $100$ $kJ$ ${mol}^{-1}$.

$E_{af}=60kJ/mol,E_{ab}=40kJ/mol$

$\Delta H=E_{af}-E_{ab}=+20kJ/mol$

$\Delta H$ is positive, reaction is endothermic.

Threshold energy is the energy that a molecule must have to make effective collision.

threshold energy is greater than activation energy.

For given reaction, threshold energy can be 100 kJ/mol.