A : At equilibrium concentration of the reactant and product does not change with time for a chemical reaction.
R : The rate of reaction is zero at equilibrium

Options

A. If both Assertion & Reason are true and the reason in the corret explanation of the assertion, then mark
B. If both assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark
C. If Assertion is true statement but Reason is false then mark
D. If both Assertion and Reason are false statements , then mark

Answer

To analyze the statements given in the question, we need to evaluate both the assertion (A) and the reason (R) provided.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "At equilibrium, the concentration of the reactant and product does not change with time for a chemical reaction."
- This is true because, at equilibrium, the rates of the forward and reverse reactions are equal, leading to constant concentrations of reactants and products.

2. **Understanding the Reason (R)**:
- The reason states that "The rate of reaction is zero at equilibrium."
- This statement is misleading. While it is true that the net change in concentration is zero (since the rates of the forward and reverse reactions are equal), the individual rates of the forward and reverse reactions are not zero. They are equal but not zero.

3. **Conclusion**:
- Since the assertion is true but the reason is false, we conclude that the correct relationship between A and R is that A is true, while R is false.

### Final Answer:
- Assertion (A) is true: At equilibrium, the concentration of the reactant and product does not change with time for a chemical reaction.
- Reason (R) is false: The rate of reaction is not zero at equilibrium; rather, the rates of the forward and reverse reactions are equal.