Sulphide ion `(S^(2-))` reacts with solid sulphur forming `S_(2)^(2-)` and `S_(3)^(2-)` with formation constants 12 and 132 respectively. Formation constant of `S_(3)^(2-)` from sulphur and `S_(2)^(2-)` is `:`

Options

A. 12
B. 132
C. `132 x 12`
D. 11

Answer

D

Explanation

`(I) " "S^(2-)+S hArr S_(2)^(2-), K_(1)=12`
`(II) " "S^(2-)+2S hArr S_(3)^(2-), K_(2)=132 `
`(III)" "S_(2)^(2-)+ShArr S_(3)^(2-), K=?`
To get eqn. (III) subtract(I) from (II)
`K=(K_(2))/(K_(1))=(132)/(12)=11`