Consider the reaction of peroxydisulfate ion (S₂O

Question

Consider the reaction of peroxydisulfate ion (S₂O₈^2-) with iodide ion (I^-) in aqueous solution:

S₂O₈^2-(aq) + 3 I^-(aq) → 2 SO₄^2-(aq) + I₃^-(aq)

At a particular temperature, the initial rate of disappearance of S₂O₈^2- varies with reactant concentrations in the following manner:

Experiment [S₂O₈^2-] (M) [I^-] (M) Initial Rate (M/s)

1 0.018 0.036 2.6 × 10^-6

2 0.027 0.036 3.9 × 10^-6

3 0.036 0.054 7.8 × 10^-6

4 0.050 0.072 1.4 × 10^-5

(a) Determine the rate law for the reaction and state the units of the rate constant.

Accepted Answer

Identify the changes in concentrations of $$S2O8^2- $$and I^- across the experiments to observe how the rate of reaction changes. This will help in determining the order of reaction with respect to each reactant.. Write the general form of the rate law for the reaction: Rate = k[$$S2O8^2$$-]^m[I^-]^n, where k is the rate constant, m is the order of the reaction with respect to $$S2O8^2$$-, and n is the order of the reaction with respect to I^-.. Use the data from the experiments to set up a system of equations based on the rate law. For each experiment, substitute the concentrations of $$S2O8^2- $$and I^- and the corresponding initial rate into the rate law equation.. Solve the system of equations to find the values of m and n. This can be done by comparing how the rate changes as the concentrations of each reactant change. If the rate changes proportionally to the concentration, the reaction is first order with respect to that reactant. If the rate changes quadratically, it is second order, and so on.. Once m and n are determined, use any of the experimental data sets to solve for k in the rate law equation. The units of k will depend on the overall order of the reaction (sum of m and n) and are generally expressed as M^(1-order) s^-1.

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Rate Law

Order of Reaction

Units of the Rate Constant (k)