2H2S(g) <-------------------->
2H2(g)Â Â +Â Â S2(g)
0.150Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â
0.375Â Â Â 0Â Â Â Â
------------------------> initial
0.150-2x                               Â
0.375 +2x    x ------------------->
equilibrium
Kc = [H2]^2 [S2]/[H2S]^2
Kc = (0.375 +2x)^2Â Â (x) /
(0.150-2x   )^2
1.67 x 10^-7 = (0.375 +2x)^2Â Â (x) /
(0.150-2x   )^2
4x^3 - 6.68 x 10^-7 x^2 + 0.141x -9.64 x 10^-8 = 0
by solving this equation
x = 6.84 x 10^-7
[S2] = x = 6.84 x 10^-7 M
equilibrium concentration = 6.84 x 10^-7 M
