[Berettagtz]

mercury sulfide disssociates as follows:

HgS to  Hg²⁺+S^2-    K_sp=5x10^-54

Then, because there are competing equlibria involved, it follows:

S^2-+H₂O to HS^-+OH^-     K_b1=0.8
and
HS^-+H₂O to H₂O + OH^-   K_b2=1.1x10^-7

Knowing the pH I need to find the following:  [H], [OH], [Hg], , [HS], [H₂S]

This problem is not hard at all, I just can't seem to get around the algebra to get the answers.  Does anyone (with better algebra than me) know how to calculate the above mentioned concentrations ?