Reaction for `6Kl+2FeCl_3 to 2Fel+6KCl+2I_2` has been found to be third order kinetically because it is supposed to occur in steps. What can be its molecularity?

Options

A. 3
B. 8
C. -1
D. 2

Answer

To determine the molecularity of the reaction \(6 \text{Kl} + 2 \text{FeCl}_3 \rightarrow 2 \text{FeI} + 6 \text{KCl} + 2 \text{I}_2\), we need to follow these steps:

### Step 1: Understand the Concept of Molecularity
Molecularity is defined as the minimum number of reactant molecules that must collide for a reaction to occur. It can also be understood as the sum of the stoichiometric coefficients of the reactants in the balanced chemical equation.

### Step 2: Identify the Reactants
In the given reaction, the reactants are:
- \(6 \text{Kl}\)
- \(2 \text{FeCl}_3\)

### Step 3: Write Down the Stoichiometric Coefficients
The stoichiometric coefficients for the reactants are:
- For \( \text{Kl} \): 6
- For \( \text{FeCl}_3 \): 2

### Step 4: Calculate the Molecularity
To find the molecularity, we sum the stoichiometric coefficients of the reactants:
\[ \text{Molecularity} = 6 + 2 = 8 \]

### Step 5: Conclusion
The molecularity of the reaction is 8.

### Final Answer
The molecularity of the reaction \(6 \text{Kl} + 2 \text{FeCl}_3 \rightarrow 2 \text{FeI} + 6 \text{KCl} + 2 \text{I}_2\) is 8.

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