2 H2S(g) ⇄ 2 H2(g) + S2(g) Kc = 9.3× 10-8 at 400ºC 0.47 moles of H2S are placed in a 3.0 L container and the system is allowed to reach equilibrium. Calculate the concentration of H2 at equilibrium.

Respuesta :

Answer: The concentration of hydrogen gas at equilibrium is [tex]1.648\times 10^{-3}M[/tex]

Explanation:

We are given:

Initial moles of hydrogen sulfide gas = 0.47 moles

Volume of the container = 3.0 L

The molarity of solution is calculated by using the equation:

[tex]\text{Molarity}=\frac{\text{Moles of solute}}{\text{Volume of the solution}}[/tex]

So, [tex]\text{Initial molarity of hydrogen sulfide gas}=\frac{0.47}{3}=0.1567M[/tex]

The given chemical equation follows:

                          [tex]2H_2S(g)\rightleftharpoons 2H_2(g)+S_2(g)[/tex]

Initial:                  0.1567

At eqllm:           0.1567-2x       2x         x

The expression of [tex]K_c[/tex] for above equation follows:

[tex]K_c=\frac{[H_2]^2[S_2]}{[H_2S]^2}[/tex]

We are given:

[tex]K_c=9.3\times 10^{-8}[/tex]

Putting values in above equation, we get:

[tex]9.3\times 10^{-8}=\frac{(2x)^2\times x}{(0.1567-2x)^2}\\\\x=8.24\times 10^{-4}[/tex]

So, equilibrium concentration of hydrogen gas = [tex]2x=(2\times 8.24\times 10^{-4})=1.648\times 10^{-3}M[/tex]

Hence, the concentration of hydrogen gas at equilibrium is [tex]1.648\times 10^{-3}M[/tex]