For the precipitation of cations of group four in the qualitative analysis, the medium is made alkaline before passing H2S gas. The purpose of alkaline solution is

Question

For the precipitation of cations of group four in the qualitative analysis, the medium is made alkaline before passing H2S gas. The purpose of alkaline solution is (A) to supress the ionisation of H2S (B) to increase the ionisation of H2S (C) to increase die ionisation of metal salt (D) to decrease die ionisation of metal salt

Tardigrade Admin · Accepted Answer

H2S leftharpoons 2H++S-2 NH4OH → NH+4+OH- H+ combines with OH- to form water and thus the first equilibrium shifts in the forward direction to increase the ionisation of H2S

Q. For the precipitation of cations of group four in the qualitative analysis, the medium is made alkaline before passing $H_{2} S$ gas. The purpose of alkaline solution is

to supress the ionisation of $H_{2} S$

to increase the ionisation of $H_{2} S$

to increase die ionisation of metal salt

to decrease die ionisation of metal salt

$H_{2} S ⇌ 2 H^{+} + S^{- 2}$
$N H_{4} O H \to N H_{4}^{+} + O H^{-}$
$H^{+}$ combines with $O H^{-}$ to form water and thus the first equilibrium shifts in the forward direction to increase the ionisation of $H_{2} S$

Q. For the precipitation of cations of group four in the qualitative analysis, the medium is made alkaline before passing H2​S gas. The purpose of alkaline solution is

to supress the ionisation of H2​S

to increase the ionisation of H2​S