If the rate of the reaction is equal to the rate constant, the order of the reaction is

Options

A. 2
B. 3
C. 0
D. 1

Explanation

To determine the order of the reaction when the rate of the reaction is equal to the rate constant, we can analyze the relationship between the rate of reaction, the rate constant, and the order of the reaction.

### Step-by-Step Solution:

1. **Understand the Rate Law**: The rate of a chemical reaction can be expressed using the rate law:
\[ R = k[A]^x \]
where:
- \( R \) is the rate of the reaction,
- \( k \) is the rate constant,
- \([A]\) is the concentration of the reactant,
- \( x \) is the order of the reaction.

2. **Set Up the Condition**: According to the problem, we have the condition:
\[ R = k \]
This means that the rate of the reaction is equal to the rate constant.

3. **Substitute into the Rate Law**: Substitute \( R \) with \( k \) in the rate law:
\[ k = k[A]^x \]

4. **Simplify the Equation**: We can simplify this equation by dividing both sides by \( k \) (assuming \( k \neq 0 \)):
\[ 1 = [A]^x \]

5. **Analyze the Implication**: The equation \( [A]^x = 1 \) implies that the concentration of the reactant raised to the power of \( x \) equals 1. This can only happen if:
- \( [A] = 1 \) (in appropriate units) or
- \( x = 0 \) (regardless of the concentration).

6. **Conclusion about the Order of Reaction**: Since the only way for the equation \( [A]^x = 1 \) to hold true for all concentrations is if \( x = 0 \), we conclude that the order of the reaction is:
\[ \text{Zero-order reaction} \]

### Final Answer:
The order of the reaction is **zero-order**.

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