Equilibrium Question 816
Question: Why only $ A{s^{3+}} $ gets precipitated as $ As_2S_3 $ and not $ Z{n^{2+}} $ as ZnS when $ H_2S $ is passed through an acidic solution containing $ A{s^{3+}} $ and $ Z{n^{2+}} $ -
Options:
A) Solubility product of $ As_2S_3 $ is less than that of ZnS
B) Enough $ A{s^{3+}} $ are present in acidic medium
C) Zinc salt does not ionise in acidic medium
D) Solubility product changes in presence of an acid
Show Answer
Answer:
Correct Answer: A
Solution:
$ K _{sp} $ of $ As_2S_3 $ is less than ZnS, In acidic medium ionisation of $ H_2S $ is suppressed (common ion effect) and $ K _{sp} $ of ZnS does not exceed.
