A saturated 0.01 M H_(2) S solution is buffered at pH =3 with exactly sufficient Pb(NO_(3))_(2) to not precipitate Pbc. K_(a)of H_(2) S = 10^(-23),K_(sp) of Pbs = 10^(-28) . The concentration of Pb^(+2) in the solution is 10^(-x) . What is x ?

A saturated 0.01 M H_(2) S solution is buffered at pH =3 with exactly

1.	A saturated 0.01 M H_(2) S solution is buffered at pH =3 with exactly sufficient Pb(NO_(3))_(2) to not precipitate Pbc. K_(a)of H_(2) S = 10^(-23),K_(sp) of Pbs = 10^(-28) . The concentration of Pb^(+2) in the solution is 10^(-x) . What is x ?
Answer» Solution :` H_2S hArr 2H^(+)+S^(_2) rArr K_a =([H^(+)]^(2) [S^(-2)])/( [H_2S]) ` ` PH =3 rArr [H^(+) ] =10 ^(_3) M` ` 10 ^(-23) =( 10 ^(-6) [S^(-2)])/( 10^(-2) )rArr [S^(-2) ] =10 ^(-19)M` ` PbShArr Pb^(+2)+S^(-2)` ` K_(sp)=[pb^(+2) ][S^(-2) ] rArr 10 ^(-28)=[pb^(+2) ] 10 ^(-19) ` ` [pb^(+2) ] =10 ^(-9) M`