Chapter 14, Problem 14.16QP

An experimenter places the following concentrations of gases in a closed container: [NOBr] = 7.13 × 10⁻² M, [NO] = 1.58 × 10⁻² M. [Br₂] = 1.29 × 10⁻² M. These gases then react:

$2\text{NOBr}(g)\stackrel{}{\rightleftharpoons }2\text{NO}(g)+{\text{Br}}_2(g)$

At the temperature of the reaction, the equilibrium constant K_c is 3.07 × 10⁻⁴. Calculate the reaction quotient, Q_c, from the initial concentrations and determine whether the concentration of NOBr increases or decreases as the reaction approaches equilibrium.

1. a Q_c = 6.33 × 10⁻⁴; the concentration of NOBr decreases
2. b Q_c = 6.33 × 10⁻⁴; the concentration of NOBr increases
3. c Q_c = 1.58 × 10⁴; the concentration of NOBr increases
4. d Q_c = 4.65 × 10⁻⁴; the concentration of NOBr decreases
5. e Q_c = 4.65 × 10⁻⁴; the concentration of NOBr increases