Chapter 4.11, Problem 2QQ

Interpretation Introduction

Interpretation:

Among the given options, the chemical formulas for a compound that contains ${\text{Al}}^{\text{3+}}$ ions and ${\text{OH}}^{\text{-}}$ ions has to be chosen.

Concept Introduction:

Chemical formulas and names for ionic compounds containing polyatomic ions:

Ionic compounds containing positive and negative charges present and those must add to get resultant charges as zero.  If more than one polyatomic ion is present in a compound, the chemical formula can be written as a polyatomic ion is enclosed in parentheses and a subscript, placed outside of the parenthesis.

Example- ${\text{Fe(OH)}}_{\text{3}}$.

Sometimes same element is present in two different locations. For example, ${\text{NH}}_{\text{4}}{\text{NO}}_{\text{3}}$- in this chemical formula “$\text{N}$” is present in two different locations as ${\text{NH}}_{\text{4}}^{\text{+}}{\text{ and NO}}_{\text{3}}^{\text{-}}$ ions.