Chapter 4, Problem 4.121EP

(a)

Interpretation Introduction

Interpretation:

The name of the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ is to be written.

Concept Introduction:

Chemical formulas and names for ionic compounds containing polyatomic ions:

Ionic compounds containing positive and negative charges present must add to zero.

If more than one polyatomic ion is present in a compound, the chemical formula can be written as a polyatomic ion is enclose in parentheses and a subscript, placed outside of the parentheses.  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 “N” is present in two different locations as ${\text{NH}}_{\text{4}}^{\text{+}}{\text{ and NO}}_{\text{3}}^{\text{-}}$ ions.

Answer to Problem 4.121EP

The name of the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ is Aluminium carbonate.

Explanation of Solution

The given name of the compound has ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ ions.

Aluminium ion has $\text{+3}$ charge and carbonate ion has $\text{-2}$ charge.  So, $\text{2:3}$ ratio of aluminium and carbonate ion produces a chemical formula ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$ with zero total charge.

Hence, the chemical formula of the compound is ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$.

The metal atom is aluminium cation and polyatomic anion is carbonate ion.

Hence, the name of the compound ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$ is aluminium carbonate.

(b)

Interpretation Introduction

Interpretation:

The chemical formula of the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ is to be written.

Concept Introduction:

Chemical formulas and names for ionic compounds containing polyatomic ions:

Ionic compounds containing positive and negative charges present must add to zero.

If more than one polyatomic ion is present in a compound, the chemical formula can be written as a polyatomic ion is enclose in parentheses and a subscript, placed outside of the parentheses.  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 “N” is present in two different locations as ${\text{NH}}_{\text{4}}^{\text{+}}{\text{ and NO}}_{\text{3}}^{\text{-}}$ ions.

Answer to Problem 4.121EP

The chemical formula of the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ is ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$.

Explanation of Solution

The given name of the compound has ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ ions.

Aluminium ion has $\text{+3}$ charge and carbonate ion has $\text{-2}$ charge.  So, $\text{2:3}$ ratio of aluminium and carbonate ion produces a chemical formula ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$ with zero total charge.

Hence, the chemical formula of the compound is ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$.

(c)

Interpretation Introduction

Interpretation:

The number of polyatomic ion present in the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ is to be identified.

Concept Introduction:

Chemical formulas and names for ionic compounds containing polyatomic ions:

Ionic compounds containing positive and negative charges present must add to zero.

If more than one polyatomic ion is present in a compound, the chemical formula can be written as a polyatomic ion is enclose in parentheses and a subscript, placed outside of the parentheses.  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 “N” is present in two different locations as ${\text{NH}}_{\text{4}}^{\text{+}}{\text{ and NO}}_{\text{3}}^{\text{-}}$ ions.

Answer to Problem 4.121EP

Three polyatomic ions present in the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$.

Explanation of Solution

The given name of the compound has ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ ions.

Aluminium ion has $\text{+3}$ charge and carbonate ion has $\text{-2}$ charge.  So, $\text{2:3}$ ratio of aluminium and carbonate ion produces a chemical formula ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$ with zero total charge.

The chemical formula of the compound is ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$.

Dissociation of ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$ is as follows.

    ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}\to {\text{ 2Al}}^{\text{3+}}{\text{+ 3CO}}_{\text{3}}^{\text{2-}}$

From the above reaction, one formula unit of aluminium carbonate (${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$) produces two monoatomic ions (${\text{Al}}^{\text{3+}}$) and three polyatomic ions (${\text{CO}}_{\text{3}}^{\text{2-}}$).

Hence, three polyatomic ions present in the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$

(d)

Interpretation Introduction

Interpretation:

The number of monoatomic ions present in the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ is to be identified.

Concept Introduction:

Chemical formulas and names for ionic compounds containing polyatomic ions:

Ionic compounds containing positive and negative charges present must add to zero.

If more than one polyatomic ion is present in a compound, the chemical formula can be written as a polyatomic ion is enclose in parentheses and a subscript, placed outside of the parentheses.  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 “N” is present in two different locations as ${\text{NH}}_{\text{4}}^{\text{+}}{\text{ and NO}}_{\text{3}}^{\text{-}}$ ions.

Answer to Problem 4.121EP

Two monoatomic ions present in the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$.

Explanation of Solution

The given name of the compound has ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$ ions.

Aluminium ion has $\text{+3}$ charge and carbonate ion has $\text{-2}$ charge.  So, $\text{2:3}$ ratio of aluminium and carbonate ion produces a chemical formula ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$ with zero total charge.

The chemical formula of the compound is ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$.

Dissociation of ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$ is as follows.

    ${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}\to {\text{ 2Al}}^{\text{3+}}{\text{+ 3CO}}_{\text{3}}^{\text{2-}}$

From the above reaction, one formula unit of aluminium carbonate (${\text{Al}}_{\text{2}}{{\text{(CO}}_{\text{3}}\text{)}}_{\text{3}}$) produces two monoatomic ions (${\text{Al}}^{\text{3+}}$) and three polyatomic ions (${\text{CO}}_{\text{3}}^{\text{2-}}$).

Hence, two monoatomic ions present in the ionic compound formed from the ions ${\text{Al}}^{\text{3+}}$ and ${\text{CO}}_{\text{3}}^{\text{2-}}$