Embibe Experts Solutions for Chapter: Qualitative Analysis, Exercise 3: Exercise-3

Write the chemical reaction associated with the "borax bead test" of cobalt $\left(\mathrm{II}\right)$.

A white sodium salt dissolves readily in water to give a solution which is neutral to litmus. When silver nitrate solution is added to the before mentioned solution, a white precipitate is obtained which does not dissolve in dilute nitric acid. The anion is:

A gas 'X' is passed through water to form a saturated solution. The aqueous solution on treatment with silver nitrate gives a white precipitate. The saturated aqueous solution also dissolves a magnesium ribbon resulting in the evolution of a colourless gas 'Y'. Identify 'X' and 'Y'.
 

The acidic aqueous solution of Ferrous ion forms a brown complex in the presence of ${\mathrm{NO}}_3^{-}$ by the following two steps :

${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}+{\mathrm{NO}}_3^{-}+{\mathrm{H}}^{+}⟶\dots \dots \dots \dots ..+{\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{3+}+{\mathrm{H}}_2\mathrm{O}$

${\left[\mathrm{Fe}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6\right]}^{2+}+\dots \dots \dots \dots \dots \dots \dots \dots .+{\mathrm{H}}_2\mathrm{O}$

Complete and balance the equations.

A dilute aqueous solution of a sodium salt forms white precipitate with ${\mathrm{MgCl}}_2$, only after boiling. The anion of the sodium salt is :

The reagent(s) that can selectively precipitate ${\mathrm{S}}^{2-}$ from a mixture of ${\mathrm{S}}^{2-}$ and $\mathrm{S}{\mathrm{O}}_4^{2-}$ in aqueous solution is (are)