Which of the following graph is correct for zero order reaction?

Options

A.
B.
C.
D.

Answer

To determine which graph correctly represents a zero-order reaction, we can follow these steps:

### Step 1: Understand the Zero-Order Reaction
A zero-order reaction is characterized by a constant reaction rate that does not depend on the concentration of the reactants. The rate equation for a zero-order reaction can be expressed as:

\[ \text{Rate} = k \]

where \( k \) is the rate constant.

### Step 2: Analyze the Rate vs. Concentration Relationship
For a zero-order reaction, the concentration of the reactant decreases linearly over time. The integrated rate law for a zero-order reaction is:

\[ [A] = [A]_0 - kt \]

where:
- \([A]\) is the concentration at time \( t \),
- \([A]_0\) is the initial concentration,
- \( k \) is the rate constant,
- \( t \) is time.

### Step 3: Determine the Graph Characteristics
Since the rate is constant and does not depend on the concentration, the graph of rate vs. concentration will be a horizontal line. This means that regardless of the concentration of the reactant, the rate remains constant.

### Step 4: Evaluate the Given Graphs
Now, we need to evaluate the provided graphs to see which one shows a constant rate regardless of concentration.

1. **Graph 1**: A line with a slope (not horizontal) - Incorrect.
2. **Graph 2**: A line with a slope (not horizontal) - Incorrect.
3. **Graph 3**: A line with a slope (not horizontal) - Incorrect.
4. **Graph 4**: A horizontal line - Correct.

### Conclusion
The correct graph for a zero-order reaction is the one that shows a horizontal line, indicating that the rate is constant and does not depend on the concentration of the reactant.

### Final Answer
The correct graph for a zero-order reaction is the one that is horizontal (Graph 4).

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