The following equilibrium constants are given:
$N_2 + 3H_2 \rightleftharpoons 2NH_3$; $K_1$
$N_2 + O_2 \rightl

Question

The following equilibrium constants are given:
$N_2 + 3H_2 \rightleftharpoons 2NH_3$; $K_1$
$N_2 + O_2 \rightleftharpoons 2NO$; $K_2$
$H_2 + \frac{1}{2}O_2 \rightleftharpoons H_2O$; $K_3$
The equilibrium constant for the oxidation of $NH_3$ by oxygen to give NO is:

Accepted Answer

The target reaction is the oxidation of $NH_3$ to NO:
$2NH_3 + \frac{5}{2}O_2 ightleftharpoons 2NO + 3H_2O$
This reaction can be obtained by adding the following reactions:
1. Reverse of reaction 1: $2NH_3 ightleftharpoons N_2 + 3H_2$; $K'_1 = \frac{1}{K_1}$
2. Reaction 2: $N_2 + O_2 ightleftharpoons 2NO$; $K_2$
3. Reaction 3 multiplied by 3: $3H_2 + \frac{3}{2}O_2 ightleftharpoons 3H_2O$; $K'_3 = K_3^3$
Adding the three reactions, we get:
$2NH_3 + \frac{5}{2}O_2 ightleftharpoons 2NO + 3H_2O$
The equilibrium constant for this net reaction is the product of the individual equilibrium constants :
$K = K'_1 	imes K_2 	imes K'_3 = \frac{1}{K_1} 	imes K_2 	imes K_3^3 = \frac{K_2K_3^3}{K_1}$

Step-by-Step Solution

Practice All CHEMISTRY Questions