Chapter 7, Problem 7.56SP

Interpretation Introduction

Interpretation:

The cation should be chosen, which does not give a precipitate with $\text{NaOH}$, ${\text{Na}}_{\text{2}}{\text{SO}}_{\text{4}}$ and $\text{KCl}$ solutions.

Concept introduction:

Precipitation reaction:

The insoluble solid (precipitate) is formed, when two soluble salt solutions are mixed together is known as precipitation reaction.

In the precipitation reaction, the compound which is going too precipitated is depends on the solubility of the compound formed in the reaction.

Water solubility of ionic compounds:

The ionic compound contains ${\text{Li}}^{\text{+,}}{\text{ Na}}^{\text{+}}{\text{, K}}^{\text{+}}{\text{, Rb}}^{\text{+}}{\text{, Cs}}^{\text{+}}{\text{ and NH}}_4{}^{+}$ ions, they are soluble in water.

Except ${\text{Ag+, Hg}}_{\text{2}}{}^{\text{2+}}{\text{, and Pb}}^{\text{2+}}$ halides, other halides ${\text{(Cl}}^{\text{-}}{\text{, Br}}^{\text{-}}{\text{, I}}^{\text{-}})$ are soluble in water.

Except sulfate of ${\text{Sr}}^{\text{2+}}{\text{, Ba}}^{\text{2+}}{\text{, Hg}}_{\text{2}}{}^{\text{2+}}{\text{, and Pb}}^{\text{2+}}$ ions, and other ${\text{NO}}_{\text{3}}{}^{-}{\text{, ClO}}_{\text{4}}{}^{\text{-}}{\text{, CH}}_{\text{3}}{\text{CO}}_{\text{2}}{}^{-}{\text{ and SO}}_{\text{4}}{}^{\text{2-}}$ ions containing compounds are soluble in water.

Except the compound contains alkali metal or ammonium cation, other carbonates, sulphides, phosphates, chromates and hydroxides, are insoluble in water.