The reaction `2A to 4B+C` follows first order kinetics. Hence, the molecularity of the reaction is:

Options

A. Unimolecular
B. Pseudo–unimolecular
C. Bimolecular
D. None of the above

Answer

To determine the molecularity of the reaction \(2A \rightarrow 4B + C\) that follows first-order kinetics, we can follow these steps:

### Step 1: Understand the Definition of Molecularity
Molecularity refers to the number of reactant molecules that are involved in a single step of a reaction. It indicates how many molecules must collide for the reaction to occur.

**Hint:** Remember that molecularity is concerned with the number of reactant molecules in an elementary reaction.

### Step 2: Identify the Reactants in the Given Reaction
In the reaction \(2A \rightarrow 4B + C\), we have only one type of reactant, which is \(A\). The coefficient in front of \(A\) indicates that two molecules of \(A\) are involved in the reaction.

**Hint:** Look at the coefficients of the reactants in the balanced equation to determine how many molecules are involved.

### Step 3: Determine the Molecularity
Since the reaction involves two molecules of \(A\), the molecularity of this reaction is 2. This means that it is a bimolecular reaction because two molecules of the same reactant are required for the reaction to proceed.

**Hint:** If a reaction involves two molecules of the same or different reactants, it is classified as bimolecular.

### Step 4: Relate Molecularity to Reaction Order
Although the reaction follows first-order kinetics, molecularity is not directly related to the order of the reaction unless it is an elementary reaction. In this case, since the reaction is not specified as elementary, we focus solely on the number of reactant molecules.

**Hint:** Remember that the order of the reaction can differ from molecularity, especially in complex reactions.

### Conclusion
The molecularity of the reaction \(2A \rightarrow 4B + C\) is 2, which classifies it as a bimolecular reaction.

**Final Answer:** The molecularity of the reaction is 2.