Chapter 7, Problem 86A

Interpretation Introduction

Interpretation:

The formula and the name of the ionic compounds formed by combining the cations and anions given in the table.

Concept introduction:

The writing of chemical formula for ionic compounds depends on the ions and the charges of the metal and non-metal elements. The naming of the compounds is based on the cation and anion present. The naming is such that cation is named first and then cation is named later ending with ‘ide’

Answer to Problem 86A

The compounds are ${\text{K}}_2{\text{SO}}_3$ - Potassium sulphite, $\text{KI}$ - Potassium Iodide, ${\text{KNO}}_3$ - Potassium Nitrate, ${\text{NH}}_4\text{I}$ - Ammonium Iodide, ${{\text{(NH}}_4\text{)}}_{\text{2}}{\text{SO}}_{\text{3}}$ - Ammonium Sulphite, ${\text{NH}}_4{\text{NO}}_3$ - Ammonium Nitrate, ${\text{Fe(NO}}_3{)}_3$ - Iron (III) Nitrate, ${\text{FeI}}_3$ - Iron (III) Iodide, ${\text{Fe}}_2{{\text{(SO}}_{\text{3}})}_3$ - Iron (III) sulphite

Explanation of Solution

The list of cations and anions are listed and naming is given below

Using Criss cross method, the formula of the compounds formed can be found as:

Cations	Anions	Formula - Names
${\text{K}}^{+}$	${\text{SO}}_3{}^{2-}$	${\text{K}}_2{\text{SO}}_3$ - Potassium sulphite
${\text{K}}^{+}$	${\text{I}}^{-}$	$\text{KI}$ - Potassium Iodide
${\text{K}}^{+}$	${\text{NO}}_3{}^{-}$	${\text{KNO}}_3$ - Potassium Nitrate
${\text{NH}}_4{}^{+}$	${\text{SO}}_3{}^{2-}$	${\text{NH}}_4\text{I}$ - Ammonium Iodide
${\text{NH}}_4{}^{+}$	${\text{I}}^{-}$	${{\text{(NH}}_4\text{)}}_{\text{2}}{\text{SO}}_{\text{3}}$ - Ammonium Sulphite
${\text{NH}}_4{}^{+}$	${\text{NO}}_3{}^{-}$	${\text{NH}}_4{\text{NO}}_3$ - Ammonium Nitrate
${\text{Fe}}^{3+}$	${\text{SO}}_3{}^{2-}$	${\text{Fe(NO}}_3{)}_3$ - Iron (III) Nitrate
${\text{Fe}}^{3+}$	${\text{I}}^{-}$	${\text{FeI}}_3$ - Iron (III) Iodide
${\text{Fe}}^{3+}$	${\text{NO}}_3{}^{-}$	${\text{Fe}}_2{{\text{(SO}}_{\text{3}})}_3$ - Iron (III) sulphite

Conclusion

The compounds are ${\text{K}}_2{\text{SO}}_3$ - Potassium sulphite, $\text{KI}$ - Potassium Iodide, ${\text{KNO}}_3$ - Potassium Nitrate, ${\text{NH}}_4\text{I}$ - Ammonium Iodide, ${{\text{(NH}}_4\text{)}}_{\text{2}}{\text{SO}}_{\text{3}}$ - Ammonium Sulphite, ${\text{NH}}_4{\text{NO}}_3$ - Ammonium Nitrate, ${\text{Fe(NO}}_3{)}_3$ - Iron (III) Nitrate, ${\text{FeI}}_3$ - Iron (III) Iodide, ${\text{Fe}}_2{{\text{(SO}}_{\text{3}})}_3$ - Iron (III) sulphite