For a single step reaction `X+2Y rarr` Products, the molecularity is

Options

A. Zero
B. `2`
C. `3`
D. `1`

Explanation

To determine the molecularity of the reaction \( X + 2Y \rightarrow \text{Products} \), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The given reaction involves one molecule of \( X \) and two molecules of \( Y \).

2. **Count the Number of Reactant Molecules**:
- From the equation, we see that:
- There is 1 molecule of \( X \).
- There are 2 molecules of \( Y \).
- Therefore, the total number of reactant molecules involved in the reaction is:
\[ 1 \, (from \, X) + 2 \, (from \, Y) = 3 \, \text{molecules} \]

3. **Define Molecularity**: Molecularity is defined as the number of reactant molecules that collide in an elementary step to form products.

4. **Conclusion**: Since a total of 3 molecules are involved in the reaction (1 from \( X \) and 2 from \( Y \)), the molecularity of the reaction is:
\[ \text{Molecularity} = 3 \]

### Final Answer:
The molecularity of the reaction \( X + 2Y \rightarrow \text{Products} \) is **3**.

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