Question

An aqueous solution contains 0.196 M hydrosulfuric acid and 0.190 M hydrochloric acid.

Calculate the sulfide ion concentration in this solution.
[S2-] = _________mol/L.

Answer 1

You CAN go through k1, transfer that data to k2 and solve for sulfide OR you can take a short cut. Here is the short cut.
H2S = 2H^+ + S^2-
k1k2 = (H2^+)(S^2-)/(H2S) and solve for S^2-.