Which of the following is an acceptable value of molecularity ?

Options

A. 5
B. 0
C. `3//2`
D. 2

Explanation

To determine the acceptable values of molecularity, we need to understand the concept of molecularity in chemical kinetics.

### Step-by-Step Solution:

1. **Definition of Molecularity**:
- Molecularity is defined as the number of reactant molecules that collide simultaneously to bring about a chemical reaction.

2. **Acceptable Values**:
- The molecularity of a reaction can only take certain integer values. Specifically, it can be:
- **1 (Unimolecular)**: Involves a single molecule undergoing a change.
- **2 (Bimolecular)**: Involves the collision of two molecules.
- **3 (Termolecular)**: Involves the simultaneous collision of three molecules.

3. **Restrictions on Molecularity**:
- Molecularity cannot be zero because at least one molecule must be involved in a reaction.
- Molecularity cannot be fractional; it must be a whole number (integer).
- Molecularity cannot exceed three in practical terms, as reactions involving more than three molecules colliding simultaneously are extremely rare.

4. **Conclusion**:
- Therefore, the acceptable values of molecularity are whole numbers: 1, 2, and 3. Any other values, such as 0 or fractions, are not acceptable.