For a reaction, the dimensions of rate constant are same as that of rate, hence order of reaction is

Options

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

Explanation

To determine the order of a reaction when the dimensions of the rate constant are the same as that of the rate, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Rate of Reaction**:
The rate of a reaction can be expressed as:
\[ \text{Rate} = k [A]^n \]
where:
- \( k \) is the rate constant,
- \( [A] \) is the concentration of the reactant,
- \( n \) is the order of the reaction.

2. **Dimensions of Rate**:
The dimensions of the rate of a reaction (change in concentration over time) can be expressed as:
\[ \text{Dimensions of Rate} = \frac{[\text{Concentration}]}{[\text{Time}]} = \frac{M}{T} \]
where \( M \) represents molarity (concentration) and \( T \) represents time.

3. **Dimensions of Rate Constant**:
The dimensions of the rate constant \( k \) depend on the order of the reaction \( n \). For a general reaction, the dimensions of \( k \) can be expressed as:
\[ \text{Dimensions of } k = \frac{M}{T} \cdot \frac{1}{[A]^n} = \frac{M}{T} \cdot \frac{1}{M^n} = \frac{M^{1-n}}{T} \]

4. **Setting Dimensions Equal**:
According to the problem, the dimensions of the rate constant are the same as that of the rate:
\[ \frac{M^{1-n}}{T} = \frac{M}{T} \]

5. **Equating the Exponents**:
Since the dimensions are equal, we can equate the exponents of \( M \):
\[ 1 - n = 1 \]
Solving for \( n \):
\[ n = 0 \]

6. **Conclusion**:
Therefore, the order of the reaction is 0.

### Final Answer:
The order of the reaction is **0**.

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