Question

For each of the questions, four choices have been provided. Select the correct alternative. Which of the following is true? (a) In an endothermic equilibrium reaction, activation energy required for a forward reaction is higher than that for a backward reaction. (b) To an endothermic equilibrium reaction, activation energy required to forward reaction is lower than that for a backward reaction. (c) Activation energy required for both forward and backward reactions is same in equilibrium. (d) No activation energy is required for an exothermic backward equilibrium reaction.

Short answer

Answer: In an endothermic equilibrium reaction, the activation energy required for the forward reaction is higher than that for the backward reaction.

Step-by-step solution

Recall Key Concepts

Recall that activation energy is the minimum amount of energy required for a chemical reaction to proceed. Endothermic reactions are those that absorb energy from their surroundings, whereas exothermic reactions release energy. In an equilibrium reaction, the rates of the forward and backward reactions are equal, and the concentrations of the reactants and products remain constant.

Evaluate Each Statement

Let's evaluate each statement: (a) In an endothermic equilibrium reaction, the activation energy required for a forward reaction is higher than that for a backward reaction. - This statement is true. In an endothermic reaction, the forward reaction requires more energy input to form products from reactants, while the backward reaction requires less energy to convert products back into reactants. (b) To an endothermic equilibrium reaction, the activation energy required for a forward reaction is lower than that for a backward reaction. - This statement is false as it contradicts the definition of endothermic reaction stated above. (c) Activation energy required for both forward and backward reactions is the same in equilibrium. - This statement is false. In equilibrium reactions, the rate of forward and backward reactions is equal, but it does not imply that the activation energies for forward and backward reactions are the same. (d) No activation energy is required for an exothermic backward equilibrium reaction. - This statement is false. Although exothermic reactions release energy, activation energy is still required to initiate the backward reaction. The activation energy for the backward reaction in an exothermic process is typically higher than the activation energy for the forward reaction. Therefore, the correct answer is:

Answer

(a) In an endothermic equilibrium reaction, activation energy required for a forward reaction is higher than that for a backward reaction.