Assertion : Sb(III) is not precipitated as su | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) $Sb(III)$ belongs to the $II$ group of qualitative analysis and is precipitated as $Sb_2S_3$ by passing $H_2S$ in an acidic medium (presence of $H

Vedclass · Accepted Answer

If both the Assertion and Reason are incorrect.

Vedclass · Answer

(D) $Sb(III)$ belongs to the $II$ group of qualitative analysis and is precipitated as $Sb_2S_3$ by passing $H_2S$ in an acidic medium (presence of $HCl$).The $HCl$ provides $H^+$ ions,which suppress the dissociation of $H_2S$ due to the common ion effect,keeping the concentration of $S^{2-}$ low,which is sufficient for $II$ group precipitation but not for higher groups.In an alkaline medium,$OH^-$ ions react with $H^+$ ions from $H_2S$ to form water $(H^+ + OH^- \rightleftharpoons H_2O)$.This shifts the equilibrium $H_2S \rightleftharpoons 2H^+ + S^{2-}$ to the right,significantly increasing the concentration of $S^{2-}$ ions.Since the concentration of $S^{2-}$ is very high in an alkaline medium,$Sb(III)$ will definitely precipitate as a sulphide.Therefore,the Assertion is false because $Sb(III)$ is indeed precipitated in an alkaline medium,and the Reason is false because the concentration of $S^{2-}$ is actually very high,not inadequate.

Assertion : $Sb(III)$ is not precipitated as sulphide when $H_2S$ is passed through its alkaline solution.
Reason : The concentration of $S^{2-}$ ion in alkaline medium is inadequate for precipitation.

Similar Questions

When $H_2S$ gas is passed into a certain solution,it reacts to form a white precipitate. The solution referred to contains ions of

Which of the following,when added to a solution of acetic acid,will decrease the concentration of hydrogen ions?

When $NH_4Cl$ is added to $NH_4OH$ solution,the dissociation of $NH_4OH$ is reduced. This is due to:

In which of the following will the dissociation of $NH_4OH$ be minimum?

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Assertion : $Sb(III)$ is not precipitated as sulphide when $H_2S$ is passed through its alkaline solution.Reason : The concentration of $S^{2-}$ ion in alkaline medium is inadequate for precipitation.