Calculate the sulfide ion concentration in a saturated H2S solution when the pH is 0.5. The concentration of H2S in a saturated H2S solution is about 0.1 mol/L.

H2S (aq) + 2H20 (l) -- 2H30+ (aq) + S2- (aq)

the Ka= 1.1x10^-21

Question

Calculate the sulfide ion concentration in a saturated H2S solution when the pH is 0.5. The concentration of H2S in a saturated H2S solution is about 0.1 mol/L. 

H2S (aq) + 2H20 (l) --> 2H30+ (aq)  + S2- (aq)

the Ka= 1.1x10^-21

lilsis76 · Answer

do I have this right, i think its (sorry I think I skipped steps), ka= products/reactants

            1.1e-21 = [0.1]2 (S)/0.1-x
the x I can assume small so.....
it would be 1.1e-21 
                  --------                =                         1.1e-19    ????
                   0.1^2

lilsis76 · Answer

@timo86m  Do you think u could help me please?

lilsis76 · Answer

what about you @Luigi0210 , do you think you can help me please?

lilsis76 · Answer

darn it >:/, its late, im going to bed, ill come back on in the morning. nite!