Which of the following graphs is not for zero order reaction?

Options

A.
B.
C.
D.

Explanation

To determine which of the given graphs is not for a zero-order reaction, we will analyze each option based on the characteristics of zero-order kinetics.

### Step-by-Step Solution:

1. **Understanding Zero-Order Reactions**:
- In a zero-order reaction, the rate of reaction is constant and does not depend on the concentration of the reactants. The rate equation is given by:
\[ \text{Rate} = k \]
- The integrated rate law for a zero-order reaction can be expressed as:
\[ [A] = [A_0] - kt \]
- The half-life of a zero-order reaction is given by:
\[ t_{1/2} = \frac{[A_0]}{2k} \]
- The concentration decreases linearly with time.

2. **Analyzing Option A**:
- The graph plots half-life (y-axis) vs. concentration (x-axis).
- Since the half-life is directly proportional to the initial concentration in zero-order reactions, this graph represents a linear relationship.
- **Conclusion**: Option A is consistent with zero-order kinetics.

3. **Analyzing Option B**:
- The graph plots concentration (y-axis) vs. time (x-axis).
- For a zero-order reaction, the concentration decreases linearly over time, which means this graph will also be a straight line.
- **Conclusion**: Option B is consistent with zero-order kinetics.

4. **Analyzing Option C**:
- The graph plots the change in concentration over time (dx/dt) vs. concentration.
- In a zero-order reaction, the rate (dx/dt) is constant, meaning this graph will show a constant value regardless of concentration.
- **Conclusion**: Option C is consistent with zero-order kinetics.

5. **Analyzing Option D**:
- The graph plots log(A - x) (y-axis) vs. time (x-axis).
- This relationship is derived from first-order kinetics, where:
\[ \log(A - x) = \log A - \frac{k}{2.303}t \]
- This indicates a linear relationship with a negative slope, characteristic of first-order reactions.
- **Conclusion**: Option D does not represent a zero-order reaction.

### Final Answer:
The graph that is not for a zero-order reaction is **Option D**.