H3AsO4 + 3I−+ 2 H3O+ H3AsO3 + I3− + H2O
The oxidation of iodide ions by arsenic acid in acidic aqueous solution occurs according to the stoichiometry shown above. The experimental rate law of the reaction is: Rate = k [H3AsO4] [I−] [H3O+]
25. What is the order of the reaction with respect to I−?
(A) 1 (B) 2 (C) 3 (D) 5 (E) 6

Explanation:

The order of reaction with respect to a species is the power at which the concentration of the species is raised in the experimental rate law.

In this case, the experimental rate law is:

Every concentration is raised to the power 1, meaning that the order with respect to any of them is 1. The overall order of the reaction is the sum of all the exponents: 1 + 1 + 1  = 3.

In conclusion, the order of the reaction with respect to I⁻ is 1.