Nitrosyl chloride is produced from the reaction of nitrogen monoxide and chlorine:
2NO(g) + Cl₂(g) → 2NOCl(g)
The following initial rates at a given temperature were obtained for the concentrations listed below.
Experiment
Initial Rate (mol·L^-1·h^-1)
[NO]₀ (mol·L^-1)
[Cl₂]₀ (mol·L^-1)
1
2) 21
0) 25
0) 25
2
19) 89
0) 75
0) 25
3
6) 63
0) 25
0) 75
From the data,what is the experimental rate law?

Question

Quizplus · Accepted Answer

The rate law can be determined by examining how the initial rate changes as the concentration of each reactant is changed. In experiment 1, only the concentration of NO changes while the concentration of Cl2 remains constant, and the initial rate decreases by a factor of 2 when [NO] is halved. This indicates that the rate depends on [NO] to the first power. In experiment 2, only the concentration of Cl2 changes while the concentration of NO remains constant, and the initial rate decreases by a factor of 2 when [Cl2] is halved. This indicates that the rate depends on [Cl2] to the first power. Therefore, the experimental rate law is Rate = k[NO][Cl2]. Note that the exponents of the concentrations cannot be determined experimentally and must be determined through further analysis (e.g. by comparing the rates of different experiments where the concentrations are changed in different ways).

Nitrosyl Chloride Is Produced from the Reaction of Nitrogen Monoxide