Chapter 4, Problem 48A

(a)

Interpretation Introduction

Interpretation: The name of the polyatomic ion ${\text{LiH}}_{\text{2}}{\text{PO}}_{\text{4}}$ needs to be determined.

Concept introduction: Polyatomic ions: An ion consisting of two or more atoms bound together.

Answer to Problem 48A

The name of the compound is lithium dihydrogen phosphate.

Explanation of Solution

Naming and Writing Formulas for More Complex Compounds

• For compounds containing both a metal and a nonmetal, the metal is always named first. The nonmetal is named from the root element name.
• If the metal ion can have more than one charge, a Roman numeral is used to specify the charge.
• For binary compounds containing only nonmetals, prefixes are used to specify the numbers of atoms present.
• The names of acids (molecules with one or more ions attached ${\text{H}}^{\text{-}}$ to an anion) depend on whether the acid contains oxygen.

Compound	Ions present	Ions name	Compound Name
${\text{LiH}}_{\text{2}}{\text{PO}}_{\text{4}}$	${\text{Li}}^{+}$ and ${\text{H}}_{\text{2}}{\text{PO}}_{\text{4}}{}^{\text{-}}$	Lithium and dihydrogen phosphate.	Lithium dihydrogen phosphate.

(b)

Interpretation Introduction

Interpretation: The name of the polyatomic ion $\text{Cu}{\left(\text{CN}\right)}_{\text{2}}$ needs to be determined.

Concept introduction:

Polyatomic ions: An ion consisting of two or more atoms bound together.

Answer to Problem 48A

The name of the compound is copper(II) cyanide.

Explanation of Solution

Naming and Writing Formulas for More Complex Compounds

• For compounds containing both a metal and a nonmetal, the metal is always named first. The nonmetal is named from the root element name.
• If the metal ion can have more than one charge, a Roman numeral is used to specify the charge.
• For binary compounds containing only nonmetals, prefixes are used to specify the numbers of atoms present.
• The names of acids (molecules with one or more ions attached ${\text{H}}^{\text{-}}$ to an anion) depend on whether the acid contains oxygen.

Compound	Ions present	Ions name	Compound Name
$\text{Cu}{\left(\text{CN}\right)}_{\text{2}}$	${\text{Cu}}^{2+}$ and ${\text{CN}}^{\text{-}}$	Copper(II) and cyanide.	Copper(II) cyanide.

(c)

Interpretation Introduction

Interpretation: The name of the polyatomic ion Pb(NO₃)₂ needs to be determined.

Concept introduction: Polyatomic ions: An ion consisting of two or more atoms bound together.

Answer to Problem 48A

The name of the compound is lead(II) nitrate.

Explanation of Solution

Naming and Writing Formulas for More Complex Compounds

• For compounds containing both a metal and a nonmetal, the metal is always named first. The nonmetal is named from the root element name.
• If the metal ion can have more than one charge, a Roman numeral is used to specify the charge.
• For binary compounds containing only nonmetals, prefixes are used to specify the numbers of atoms present.
• The names of acids (molecules with one or more ions attached ${\text{H}}^{\text{-}}$ to an anion) depend on whether the acid contains oxygen.

Compound	Ions present	Ions name	Compound Name
Pb(NO3)2	${\text{Pb}}^{\text{2+}}$ and ${\text{NO}}_3{}^{-}$	Lead(II) and nitrate.	Lead(II) nitrate.

Conclusion

When a metal is present that forms more than one cation, a Roman numeral is required to specify the cation charge.

(d)

Interpretation Introduction

Interpretation: The name of the polyatomic ion ${\text{Na}}_{\text{2}}{\text{HPO}}_{\text{4}}$ needs to be determined.

Concept introduction: Polyatomic ions: An ion consisting of two or more atoms bound together.

Answer to Problem 48A

The name of the compound is sodium hydrogen phosphate.

Explanation of Solution

Naming and Writing Formulas for More Complex Compounds

• For compounds containing both a metal and a nonmetal, the metal is always named first. The nonmetal is named from the root element name.
• If the metal ion can have more than one charge, a Roman numeral is used to specify the charge.
• For binary compounds containing only nonmetals, prefixes are used to specify the numbers of atoms present.
• The names of acids (molecules with one or more ions attached ${\text{H}}^{\text{-}}$ to an anion) depend on whether the acid contains oxygen.

Compound	Ions present	Ions name	Compound Name
${\text{Na}}_{\text{2}}{\text{HPO}}_{\text{4}}$	${\text{Na}}^{\text{+}}$ and ${\text{HPO}}_{\text{4}}{}^{\text{2-}}$	Sodium and hydrogen phosphate.	Sodium hydrogen phosphate.

Conclusion

When a metal is present that forms more than one cation, a Roman numeral is required to specify the cation charge.

(e)

Interpretation Introduction

Interpretation: The name of the polyatomic ion ${\text{NaClO}}_2$ needs to be determined.

Concept introduction: Polyatomic ions: An ion consisting of two or more atoms bound together.

Answer to Problem 48A

The name of the compound is sodium chlorite.

Explanation of Solution

Naming and Writing Formulas for More Complex Compounds

• For compounds containing both a metal and a nonmetal, the metal is always named first. The nonmetal is named from the root element name.
• If the metal ion can have more than one charge, a Roman numeral is used to specify the charge.
• For binary compounds containing only nonmetals, prefixes are used to specify the numbers of atoms present.
• The names of acids (molecules with one or more ions attached ${\text{H}}^{\text{-}}$ to an anion) depend on whether the acid contains oxygen.

Compound	Ions present	Ions name	Compound Name
${\text{NaClO}}_2$	${\text{Na}}^{\text{+}}$ and ${\text{ClO}}_2{}^{-}$	Sodium and chlorite.	Sodium chlorite.

Conclusion

When a metal is present that forms more than one cation, a Roman numeral is required to specify the cation charge.

(f)

Interpretation Introduction

Interpretation: The name of the polyatomic ion ${\text{Co}}_{\text{2}}{\left({\text{SO}}_{\text{4}}\right)}_{\text{3}}$ needs to be determined.

Concept introduction: Polyatomic ions: An ion consisting of two or more atoms bound together.

Answer to Problem 48A

The name of the compound is cobalt(III) sulfate.

Explanation of Solution

Naming and Writing Formulas for More Complex Compounds

• For compounds containing both a metal and a nonmetal, the metal is always named first. The nonmetal is named from the root element name.
• If the metal ion can have more than one charge, a Roman numeral is used to specify the charge.
• For binary compounds containing only nonmetals, prefixes are used to specify the numbers of atoms present.
• The names of acids (molecules with one or more ions attached ${\text{H}}^{\text{-}}$ to an anion) depend on whether the acid contains oxygen.

Compound	Ions present	Ions name	Compound Name
${\text{Co}}_{\text{2}}{\left({\text{SO}}_{\text{4}}\right)}_{\text{3}}$	${\text{Co}}^{\text{3+}}$ and ${\text{SO}}_4{}^{2-}$	Cobalt(III) and sulfate	Cobalt(III) sulfate