Even at high temperatures, the formation of NO is not favored: (Kc = 4.10 × 10−4 at 2000°C) N2(g) + O2(g) ⇌ 2 NO(g) What is [NO] when a mixture of 0.20 mol of N2(g) and 0.15 mol of O2(g) reach equilibrium in a 1.0−L container at 2,000°C?

Respuesta :

Answer: The equilibrium concentration of NO is 0.0034 M

Explanation:

We are given:

Initial moles of nitrogen gas = 0.20 moles

Initial moles of oxygen gas = 0.15 moles

Volume of container = 1.0 L

We know that:

[tex]\text{Molarity}=\frac{\text{Number of moles}}{\text{Volume}}[/tex]

So, [tex]\text{Molarity of }N_2=\frac{0.20}{1}=0.20M[/tex]

[tex]\text{Molarity of }O_2=\frac{0.15}{1}=0.15M[/tex]

The given chemical reaction follows:

                     [tex]N_2(g)+O_2(g)\rightleftharpoons 2NO(g)[/tex]

Initial:             0.20     0.15

At eqllm:      0.20-x    0.15-x      2x

The expression of [tex]K_c[/tex] follows:

[tex]K_c=\frac{[NO]^2}{[N_2]\times [O_2]}[/tex]

We are given:

[tex]K_c=4.10\times 10^{-4}[/tex]

Putting values in above equation, we get:

[tex]4.10\times 10^{-4}=\frac{(2x)^2}{(0.20-x)\times (0.15-x)}\\\\x=-0.0018,0.0017[/tex]

Neglecting the negative value of 'x' because concentration cannot be negative.

So, equilibrium concentration of NO = 2 x = (2 × 0.0017) = 0.0034 M

Hence, the equilibrium concentration of NO is 0.0034 M