Question

The equilibrium constant, K, for the following reaction is 0.186 at 332 K.

• NH₄HS(s) (equilibrium) NH₃(g) + H₂S(g)

An equilibrium mixture in a 16.2 L container at 332 K contains 0.322 mol  NH₄HS(s), 0.543 M NH₃ and 0.343 M H₂S. What will be the concentrations of the two gases once equilibrium has been reestablished, if the equilibrium mixture is compressed at constant temperature to a volume of 8.20 L?

[NH3]	=	M
[H2S]	=	M

Answer 1

Concentration of NH3, [NH,1- (16.2 L) (0.543M= 1.07M 8.20 L Concentrati on of H2S, [H,S/= 16.2 L) (0.343M - 0.678M 8.20 L Equilibrium equation is as follows NH SH(s) Equilibrium constant, K [NH H,S] H2S(g) NH,(g) Since NH4SHis a solid, we can take its concentrati on as unity and exclude it from the equilibrium constant expression The ICE table H2S(g) NHSH s) NH3(g) I(M) с (м): E(M) 1.07 0.678 x 1.07+x 0.678+x Equilibrium constant, K = [NH3][H2S] 0.186=(1.07+x)(0.678+x) 0.400 According to ICE table, Concentration of NH3, [NH3 (1.07+x) M (1.07+0.400) M 0.670M Concentrati on of H2S, [H2S] = (0.678+x) M (0.678+(-0.400) M 0.278 M