A : The rate constant of zero order reaction is equal to rate of reaction.
R : `t_(1//2)` for zero order reaction is directly proportional to initial concentration.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion , then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion , then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements , then mark (4)

Answer

To solve the question, we need to analyze both the assertion (A) and the reason (R) provided.

### Step 1: Analyze the Assertion (A)
The assertion states: "The rate constant of a zero-order reaction is equal to the rate of the reaction."

- In a zero-order reaction, the rate of reaction is independent of the concentration of the reactants. The rate can be expressed as:

\[ \text{Rate} = k \]

where \( k \) is the rate constant. Since the rate does not depend on the concentration of the reactants, the rate constant \( k \) is indeed equal to the rate of the reaction.

**Conclusion for Assertion (A)**: The assertion is **True**.

### Step 2: Analyze the Reason (R)
The reason states: "The half-life (\( t_{1/2} \)) for a zero-order reaction is directly proportional to the initial concentration."

- The half-life for a zero-order reaction can be calculated using the formula:

\[ t_{1/2} = \frac{[A]_0}{2k} \]

where \([A]_0\) is the initial concentration and \( k \) is the rate constant. From this equation, we can see that the half-life \( t_{1/2} \) is directly proportional to the initial concentration \([A]_0\).

**Conclusion for Reason (R)**: The reason is also **True**.

### Step 3: Determine the Relationship Between A and R
Now, we need to determine if the reason correctly explains the assertion.

- While both statements are true, the reason does not explain the assertion. The assertion is about the equality of the rate constant and the rate of reaction, while the reason discusses the relationship between half-life and initial concentration. Hence, the reason does not provide a valid explanation for the assertion.

### Final Conclusion
- Both A and R are true, but R does not explain A. Therefore, the correct answer is:
**Both assertion and reason are true, but the reason is not the correct explanation for the assertion.**

---