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 second
2. Cation - name the element
3. Anion - change end of element
name to -ide
Examples
- NaCl
Na+
sodium chloride
Cl-
- MgO
Mg2+ O2magnesium oxide
- CaS
Ca2+ S2calcium sulfide
Type 2 - metal forms more than one
cation (Table 5.2 p. 128)
1. Cation first, anion second
2. Cation charge is specified by a
Roman numeral in parentheses
Examples
- CuCl
Cu?+ Clcopper(I) chloride
Fe?+ O20 = 2(?) - 3(2-)
6 = 2(?)
3=?
iron(III) oxide
- PbCl4
Pb?+ Cl0 = ? + 4(-1)
4=?
lead(IV) chloride
-Fe2O3
Strategy for binary compounds
Decide if the cation has only one charge
or can have multiple charges
If cation has one charge, name both
ions
b. If cation can have multiple charges, use
Roman numeral in parentheses to show
the charge
a.
Type III - contains only nonmetals
1. 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
N 2O 5
dinitrogen 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
ClOhypochlorite
ClO2chlorite
ClO3chlorate
ClO4perchlorate
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 acid
HCl - hydrochloric acid
2. If anion contains oxygen
root name of central atom
*anion ends with ate - suffix -ic acid
Example
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.
Examples
calcium chloride
Ca2+ Cl- ---> CaCl2
dinitrogen pentoxide
N 2O 5
sodium carbonate
Na+
CO32- ---> Na2CO3
nitric acid
nitrate NO3- ---> HNO3
lead(IV) oxide
Pb4+ O2- --->
PbO2