In the presence of HCl,H_2S results in the pr | vedclass

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

Question

(C) The dissociation of $H_2S$ is given by the equilibrium: $H_2S \rightleftharpoons 2H^+ + S^{2-}$.In the presence of $HCl$,the concentration of $H^+

Vedclass · Accepted Answer

lower concentration of $S^{2-}$

Vedclass · Answer

(C) The dissociation of $H_2S$ is given by the equilibrium: $H_2S \rightleftharpoons 2H^+ + S^{2-}$.In the presence of $HCl$,the concentration of $H^+$ ions increases significantly.According to the common ion effect,this shift in equilibrium suppresses the dissociation of $H_2S$,resulting in a lower concentration of $S^{2-}$ ions.Group-$2$ metal sulfides have very low solubility products $(K_{sp})$,so they precipitate even at this low $S^{2-}$ concentration.Group-$4$ metal sulfides have higher $K_{sp}$ values and require a higher $S^{2-}$ concentration to precipitate,which is not achieved in the presence of $HCl$.

In the presence of $HCl$,$H_2S$ results in the precipitation of Group-$2$ elements but not Group-$4$ elements during qualitative analysis. It is due to

Similar Questions

When $0.05 \ M$ dimethylamine is dissolved in $0.1 \ M$ $NaOH$ solution,the percentage dissociation of dimethylamine is: $(K_b)_{(CH_3)_2NH} = 5 \times 10^{-4}$

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.

In the precipitation of the iron group in qualitative analysis,ammonium chloride is added before adding ammonium hydroxide to:

The following equilibrium exists in aqueous solution: $CH_3COOH \rightleftharpoons CH_3COO^{-} + H^{+}$. If dilute $HCl$ is added without a change in temperature,then the:

$H_2S$ will precipitate the sulphides of all the metals from the solution of chlorides of $Cu, Zn$ and $Cd,$ if

Vedclass Test Series

Exam Paper Generator

Online Exam Module