A buffer solution is 0.25 M `CH_3COOH -0.15 M CH_3COONa,` saturated in `H_2S` (0.1 M) and has `[Mn^(2+)] =0015 M. K_a (CH_3COOH)= 1.74 xx 10^(-5)`.
`K_(a) (H_(2)S)=1.1 xx 10^(-21) and K_(sp) (MnS)=2.5 xx 10^(-13)`.
(a) Will MnS precipitate?
(b) Which buffer component should be increased in concentration and to which minimum value of just start precipitation of MnS?

Answer

(a) No (b) `[CH_(3)OO^(-)] =1.7 M`