The correct explanation for the effect of catalyst on the rate of reversible reaction is

Options

A. It displaces the equilibrium state on right side
B. It increases the kinetic energy of reacting molecules
C. It provides a new reaction path of low activation energy
D. It decreases the the velocity of backward reaction

Answer

To understand the effect of a catalyst on the rate of a reversible reaction, we can break down the explanation into a few key steps:

### Step-by-Step Solution:

1. **Understanding Reversible Reactions**:
- A reversible reaction is one where the reactants can form products, and the products can also revert back to the reactants. This means that both the forward and backward reactions are occurring.

**Hint**: Remember that in reversible reactions, both the forward and reverse processes are significant.

2. **Activation Energy**:
- Activation energy is the minimum energy required for a reaction to occur. For a reversible reaction, there are two activation energies: one for the forward reaction and one for the backward reaction.

**Hint**: Activation energy is crucial for understanding how reactions proceed.

3. **Role of Catalysts**:
- A catalyst is a substance that increases the rate of a reaction without being consumed in the process. It does this by providing an alternative reaction pathway with a lower activation energy for both the forward and backward reactions.

**Hint**: Catalysts lower the energy barrier for reactions, making them proceed faster.

4. **Effect on Equilibrium**:
- While a catalyst speeds up both the forward and backward reactions equally, it does not affect the position of equilibrium. This means that the concentrations of reactants and products at equilibrium remain unchanged.

**Hint**: A catalyst does not change the equilibrium constant; it only helps reach equilibrium faster.

5. **Conclusion**:
- The correct explanation for the effect of a catalyst on the rate of a reversible reaction is that it provides a new reaction path with lower activation energy for both the forward and backward reactions, thus increasing the rates of both reactions equally.

**Hint**: Focus on the concept that catalysts affect the rate of reactions but not the equilibrium position.

### Final Answer:
The correct explanation for the effect of a catalyst on the rate of a reversible reaction is that it provides a new reaction path of low activation energy.