Sulphide ions in alkaline solutircn react with solid sulphur to form polyvalent sulphide ions. The equilibrium constant for the formation of $S_{2}^{2 -} and S_{3}^{2 -}$ from S and S^2-ions are 1.7 and 5.3 respectively. Equilibrium constant for the formation of $S_{3}^{2 -}$ from $S_{2}^{2 -}$ and S is:

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

1.33

3.11

4.21

1.63

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Given, $S (s) + S^{2 -} ⇌ S_{2}^{2 -} K_{c_{1}} = 1 .7$
$2 S (s) + S^{2 -} ⇌ S_{3}^{2 -} K_{c_{2}} = 5 .3$
$\begin{array}{l} ∴ K_{C_{1}} = \frac{[S_{2}^{2 -}]}{[S^{2 -}]} = 1 .7 . . . . . (i) \\ K_{c_{2}} = \frac{[S_{3}^{2 -}]}{[S^{2 -}]} = 5 .3 . . . . . (ii) \end{array}$
Now for,
$\begin{array}{l} S_{2}^{2 -} (s) + S (s) ⇌ S_{3}^{2 -} \\ K_{c} = \frac{[S_{3}^{2 -}]}{[S_{2}^{2 -}]} \end{array}$
$∴$ By Eqs.(ii) and (i), $\frac{K_{c_{2}}}{K_{c_{1}}} = \frac{[S_{3}^{2 -}]}{[S_{2}^{2 -}]} = K_{c}$
$∴$ K_c = 3.11