The unit of rate constant for zero order reaction is :

Options

A. `s^(-1)`
B. mol `L^(-1)s^(-1)`
C. `L mol^(-1)s^(-1)`
D. `L^(2)mol^(-2)s^(-1)`

Explanation

To determine the unit of the rate constant for a zero-order reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Zero-Order Reaction**:
In a zero-order reaction, the rate of reaction is constant and does not depend on the concentration of the reactants. The rate can be expressed as:
\[ \text{Rate} = k \]
where \( k \) is the rate constant.

2. **Rate Expression**:
The rate of a zero-order reaction can also be expressed in terms of concentration change over time:
\[ \text{Rate} = -\frac{d[A]}{dt} \]
where \([A]\) is the concentration of the reactant.

3. **Unit of Rate**:
The unit of rate is typically expressed in terms of concentration per unit time. For concentration, we use molarity (M), which is moles per liter (mol/L). Therefore, the unit of rate can be expressed as:
\[ \text{Unit of Rate} = \frac{\text{moles}}{\text{liters} \cdot \text{seconds}} = \text{mol L}^{-1} \text{s}^{-1} \]

4. **Unit of Rate Constant \( k \)**:
Since for a zero-order reaction, the rate is equal to the rate constant \( k \), we can conclude that:
\[ k = \text{Rate} \]
Thus, the unit of the rate constant \( k \) for a zero-order reaction is:
\[ k = \text{mol L}^{-1} \text{s}^{-1} \]

### Final Answer:
The unit of the rate constant for a zero-order reaction is \( \text{mol L}^{-1} \text{s}^{-1} \).