Chapter 4.2, Problem 1RQ

Interpretation Introduction

Interpretation: The pattern of the polyatomic ions which is easy to memorize needs to be explained.

Concept Introduction: The polyatomic ions are positive or negative charged ions which are formed from 2 or more than 2 atoms. The overall charge on the group of atoms will be the charge on the polyatomic ion.

Explanation of Solution

As per the hint, the polyatomic ions in the mentioned table can be grouped according to the common elements present in the ions or suffixes used to name them.

To memorize the smaller number of polyatomic ions, they can be grouped on the basis of elements present in them.

The different types of polyatomic ions will be:

Polyatomic ions containing carbon atom.

Polyatomic ions containing nitrogen atom.

Polyatomic ions containing phosphorus atom.

Polyatomic ions containing sulfur atom.

Polyatomic ions containing chlorine atom.

The examples of polyatomic ions containing carbon atom are as follows:

  $\begin{array}{l}{\text{Carbonate-CO}}_3^{2-}\\ {\text{Hydrogen carbonate-HCO}}_3^{-}\\ {\text{Cyanide-CN}}^{-}\end{array}$

The examples of polyatomic ions containing nitrogen atom are as follows:

  $\begin{array}{l}{\text{Nitrate-NO}}_3^{-}\\ {\text{Nitrite-NO}}_2^{-}\\ {\text{Ammonium-NH}}_4^{+}\end{array}$

The examples of polyatomic ions containing phosphorus atom are as follows:

  $\begin{array}{l}{\text{Hydrogen phosphate:HPO}}_4^{2-}\\ {\text{Phosphate:PO}}_4^{3-}\end{array}$

The examples of polyatomic ions containing sulfur atom are as follows:

  $\begin{array}{l}{\text{Sulfite-SO}}_3^{2-}\\ {\text{Hydrogen sulfate-HSO}}_4^{-}\\ {\text{Sulfate-SO}}_4^{2-}\end{array}$

The examples of polyatomic ions containing chlorine atom are as follows:

  $\begin{array}{l}{\text{Chlorite-ClO}}^{-}\\ {\text{Chlorate-ClO}}_3^{-}\\ {\text{Perchlorate-ClO}}_4^{-}\end{array}$

The other polyatomic ions are as follows:

  $\begin{array}{l}{\text{Dichromate-Cr}}_{\text{2}}{\text{O}}_7^{2-}\\ {\text{Acetate-C}}_{\text{2}}{\text{H}}_{\text{3}}{\text{O}}_2^{-}\\ {\text{Chromate-Cr}}_{\text{2}}{\text{O}}_7^{2-}\\ {\text{Peroxide-O}}_2^{2-}\end{array}$