Question

The initial-rate data in the table above were obtained for the reaction represented below. 2 NO(g) + O2(g) NO2(g) Experi ment Initial Initial Initial Rate [NO] [O2] of Formation (mol L-1) (mol L-1) of NO2 (mol L-1,-1) 0.10 0.10 2.5 x 10-4 0.20 0.10 5.0 x 10-4 0.20 0.40 8.0 x 10-3 1 2 3 What is the experimental rate law for the reaction?

Answer 1

The experimental rate law for the given reaction is Rate = k[NO]1[O2]2, indicating first-order dependence on NO and second-order dependence on O2.

Step-by-step explanation:

The initial-rate data provided indicate how the reaction rate changes with variations in the concentrations of the reactants NO and O2. By analyzing these changes, we can determine the experimental rate law for the reaction in question.

From the data, comparing experiments 1 and 2, the doubling of [NO] while keeping [O2] constant results in a doubling of the rate, suggesting first-order dependence on [NO].

This relationship is represented by rate ∝ [NO]1. Similarly, comparing experiments 1 and 3, when the concentration of [O2] is quadrupled with a constant [NO], the rate increases by a factor of 16 (which is 42), indicating second-order dependence on [O2], or rate ∝ [O2]2. Therefore, the rate law for the reaction can be written as Rate = k[NO]1[O2]2, where k is the rate constant.