A1.0 m h2s solution has a ph = 3.75 at equilibrium. what is the value of ka?
3.16 × 10−21
3.16 × 10−8
8.89 × 10−5
8.89 × 10−8

When H2S dissociates, the equation is H2S= 2H+ + S2-. In this case, the H+ concentration can be determined from the pH 3.75. taking 10^-pH, H+ is equal to 1.7783 x10^-4 M. Ka is expressed [H+]^2[S2-]/[H2S], this is equal to [1.7783 x10^-4 M]^2 [1.7783 x10^-4 M]/ [1.0-1.7783 x10^-4 M] or 5.62 x10^-12.