Nomenclature

Naming Compounds

Binary Compounds- composed of two elements

1. Contain a metal and a nonmetal

2. Contain two nonmetals

Binary Ionic Compounds- cation (metal ion)- anion (nonmetal ion)

Type I - metal forms only one ion (Table 5.1 p. 125)

1. Cation first, anion second2. Cation - name the element3. Anion - change end of element

name to -ide

Examples- NaCl Na+ Cl-

sodium chloride

- MgO Mg2+ O2-

magnesium oxide

- CaS Ca2+ S2-

calcium sulfide

Type 2 - metal forms more than one cation (Table 5.2 p. 128)

1. Cation first, anion second2. Cation charge is specified by a

Roman numeral in parentheses

Examples- CuCl Cu?+ Cl-

copper(I) chloride

-Fe2O3 Fe?+ O2-

0 = 2(?) - 3(2-)6 = 2(?)3 = ?

iron(III) oxide- PbCl4 Pb?+ Cl-

0 = ? + 4(-1)4 = ?

lead(IV) chloride

Strategy for binary compounds

Decide if the cation has only one charge or can have multiple charges

a. If cation has one charge, name both ions

b. If cation can have multiple charges, use Roman numeral in parentheses to show the charge

Type III - contains only nonmetals1. First element in formula is named

first using full element name.2. Second element is named as though

it were an anion (-ide ending).3. Prefixes are used to denote the

number of atoms present (Table 5.3 p. 132)

4. Never use mono for naming first element.

Examples

BF3 boron trifluoride

NO nitrogen monoxide

N2O5dinitrogen pentoxide

Polyatomic ions- ion composed of several atoms, but are bound together so they act as one unit- Table 5.4 p. 137-oxyanion - series of polyatomic ions that contain an atom of a given element and different numbers of oxygen atoms

ClO- hypochloriteClO2- chloriteClO3- chlorateClO4- perchlorate

Examples

Na2SO4 sodium sulfate

KH2PO4 potassium dihydrogen phosphate

Mn(OH)2 manganese hydroxide

NH4ClO3 ammonium chlorate

Naming Acids

Compounds that produce H+ ions when dissolved in water

1. If anion does NOT contain oxygen*prefix hydro-, suffix -ic acid

Examples

H2S - hydrosulfuric acidHCl - hydrochloric acid

2. If anion contains oxygenroot name of central atom

*anion ends with ate - suffix -ic acidExample

H2SO4 - sulfate ion - sulfuric acid*anion ends with ite - suffix -ous acid

Example

HNO2 - nitrite ion - nitrous acid

Writing formulas from names

Use names of elements to write the formula. You must check the charges of the ions (including polyatomic ions) to make sure the net charge on the compound is zero.

Examplescalcium chloride Ca2+ Cl- ---> CaCl2dinitrogen pentoxide

N2O5

sodium carbonate Na+ CO3

2- ---> Na2CO3

nitric acidnitrate NO3- ---> HNO3

lead(IV) oxidePb4+ O2- ---> PbO2