The order of the following reaction will be:
\(2FeCl_3 + SnCl_2 \longrightarrow 2FeCl_2 + SnCl_4\)
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 3
The order of a reaction is the sum of the powers of the concentration terms in the rate law, and it is found by experiment. For the reduction of ferric chloride by stannous chloride, the rate is found to depend on the square of the \( \ce{FeCl3} \) concentration and the first power of the \( \ce{SnCl2} \) concentration:
\( \ce{2FeCl3 + SnCl2 -> 2FeCl2 + SnCl4} \)
Rate = k[FeCl3]2[SnCl2]1 ⇒ order = 2 + 1 = 3
It is a standard example of a third order reaction; here the order happens to equal the sum of the stoichiometric coefficients (2 + 1).
Note: The question is from beyond the NCERT textbook.