The order of the following reaction will be:

\(2FeCl_3 + SnCl_2 \longrightarrow 2FeCl_2 + SnCl_4\)

3

The correct answer is option 1. 3.

The order of a reaction refers to the power to which the concentration of a reactant is raised in the rate law equation. It indicates how the rate of the reaction depends on the concentration of each reactant.

The rate law of a reaction is an equation that relates the rate of reaction to the concentration of the reactants. For a general reaction \(aA + bB \rightarrow \text{products}\), the rate law is expressed as:

\(\text{Rate} = k [A]^m [B]^n\)

Here, \(k\) is the rate constant, and \(m\) and \(n\) are the orders with respect to reactants \(A\) and \(B\), respectively.

The overall order of the reaction is the sum of the powers of the concentration terms in the rate law equation. For the rate law above, the total order is \(m + n\).

Applying to the Given Reaction:

For the reaction:

\(2FeCl_3 + SnCl_2 \rightarrow 2FeCl_2 + SnCl_4\)

An elementary reaction is a single-step reaction where the rate law can be directly written from the balanced chemical equation. If we assume the reaction is elementary, the coefficients in the balanced equation provide the exponents in the rate law.

From the balanced equation:

\(2FeCl_3 + SnCl_2 \rightarrow 2FeCl_2 + SnCl_4\)

We can write a possible rate law as:

\(\text{Rate} = k [FeCl_3]^2 [SnCl_2]^1\)

Here, the concentration of \(FeCl_3\) is raised to the power 2 (because of its coefficient 2), and the concentration of \(SnCl_2\) is raised to the power 1 (because of its coefficient 1).

The order with respect to \(FeCl_3\) is 2.

The order with respect to \(SnCl_2\) is 1.

The overall order of the reaction is the sum of these exponents:

\(\text{Overall Order} = 2 + 1 = 3\)

Conclusion:

The overall order of the reaction, based on the assumption that it is elementary and follows the stoichiometry of the balanced equation, is 3.

So, the correct answer is Option 1: 3