Calculatethe potential of a half cell having reaction : Ag_2 S (s) + 2e^- iff 2Ag (S) + S^(2-) (aq) in asolution buffered at p^(H) =3 and which is also saturated with0.1 MH_2S (aq) [Given : K_(sp)(Ag_2 S ) = 2 xx 10^(-49) , K_(a1). K_(a2) = 1.1 xx 10^(-21) , E_(As^(+) //Ag)^(@) = 0.8V]

Calculatethe potential of a half cell having reaction : Ag_2 S (s) + 2

1.	Calculatethe potential of a half cell having reaction : Ag_2 S (s) + 2e^- iff 2Ag (S) + S^(2-) (aq) in asolution buffered at p^(H) =3 and which is also saturated with0.1 MH_2S (aq) [Given : K_(sp)(Ag_2 S ) = 2 xx 10^(-49) , K_(a1). K_(a2) = 1.1 xx 10^(-21) , E_(As^(+) //Ag)^(@) = 0.8V]
Answer» `-0.19 V ` `0.19 ` ` 1.18 V ` `-0.166 V ` SOLUTION :`K_a = K_(a1). K_(a_2) = ((H^(OPLUS))^(2)(S^(-2)))/([H_2S]) `........... (1) , `K_(sp) = [Ag^(oplus)][S^(-2)] `........ (2) `((1))/((2)) = (K_(a))/(K_(sp))=([H^(oplus)]^(2))/([H_2S]) xx ([S^(2)])/([Ag^(ox)][S^(-2)]), (1.1 xx 10^(-21))/(2 xx 10^(-49)) = (10^(-6) xx 1)/( 0.1 xx [Ag^(oplus)]) implies (Ag^(oplus)) = 4.264 xx 10^(-17) M` ` E_(S^(-2)) .// Ag_2S // Ag =E_(Ag^(+)//Ag)^(0) to (0.859)/(1-1) , E = 0.8 - (0.0591)/(1) log""((1)/(4.264 xx 10^(-17)))` `=0.8p + (0.0591 xx-16.37 ) = (0.8 - 0.9675 ) , E = - 0.166`