Ionic Nomenclature

D.1 Intro: Elements, Compounds and Nomenclature

• Chemical nomenclature: the organized system used to name substances and write their chemical formulas.

Chemical formula: represents the number of each kind of atom bonded together in a substance.

Subscript: indicates the number of atoms or ions present in the formula.

Example (formula for water):

D.1 Intro: Elements, Compounds and Nomenclature

D.2 The History of Chemical Nomenclature

• Lavoisier’s system of nomenclature is sometimes called the Classical System.This system of naming is used to the present

day.

Common Name Systematic Name

fixed air carbon dioxide

cinnabar mercuric sulfide

D.2 The History of Chemical Nomenclature

• Chemical formulas of compounds…are written using two or more symbols

side by side.use subscripts to make the formulas more

compact.

Example: carbon dioxideDalton formula: Berzelius formula: CO2

D.2 The History of Chemical Nomenclature

• Many elements form several compounds with another given element.Lavoisier’s Classical System was modified to

include suffixes to name these compounds:

Examples:

ferric oxide Fe2O3

ferrous oxide FeO(More will be said on this in Section D.6.)

D.2 The History of Chemical Nomenclature

Examples:

ChemicalFormula

ClassicalSystem

StockSystem

FeCl2 ferrous chloride iron(II) chloride

FeCl3 ferric chloride iron(III) chloride

FeO ferrous oxide iron(II) oxide

Fe2O3 ferric oxide iron(III) oxide

D.3 Classification of Compounds

• Ionic compounds are formed when oppositely charged ions are attracted to each other.Strong electrostatic attractions.High melting point and boiling point solids.Capable of dissolving in water.

D.3 Classification of Compounds

• Cations are positively-charged ions.Examples: Na+, K+, Ca2+, Al3+, Fe3+

Anions are negatively-charged ions.Examples:

Cl–, F–, S2–, Se2–, P3–

D.3 Classification of Compounds

• Molecular compounds are pure substances composed of atom groupings called molecules.strong covalent bonds between atoms

atoms share electrons each atom has a noble-gas electron arrangement

possess weak bonds between moleculeslow melting point and boiling point gases,

liquids and solids

D.4 Binary Ionic Compounds Molecular Formula:

Chemical formula for molecular substances. The actual number of each kind of atom

present in the molecule.

Empirical Formula: Indicates the simplest whole number ratio of

atoms or ions in the compound.

D.4 Binary Ionic Compounds• Naming Binary Ionic Compounds

When naming any ionic compounds, simply write the name of the positive ion followed by the name of the negative ion.

The rules for naming simple ions were given in Unit B.

D.4 Binary Ionic Compounds1. Name the cation by writing the full

name of the metallic element. Na+ is a sodium ion Zn2+ is a zinc ion Al3+ is an aluminum ion.

2. Name the anion by abbreviating the full name of the nonmetallic element and adding –ide. Cl– is a chloride ion S2– is a sulfide ion P3– is a phosphide ion

D.4 Binary Ionic CompoundsExamples: NaCl {from Na+Cl–}

sodium chlorideSodium chloride is table salt.

CaCl2 {from Ca2+(Cl–)2}

calcium chlorideCalcium chloride is a drying agent also used to melt ice.

D.4 Binary Ionic Compounds• Writing Chemical Formulas for Binary

Ionic Compounds1. When given the name of the ionic

compound, first write the symbols for the ions involved.

2. Next, determine the lowest whole number ratio of ions that will provide an overall net charge of zero. (Criss-Cross)

D.4 Binary Ionic CompoundsExamples:

D.4 Binary Ionic CompoundsExamples:

D.4 Binary Ionic CompoundsExamples: