I. Naming compounds: (Ch. 7 in the textbook)
1. Compounds are written with the positive part first. If you’re not sure which part is positive,
check the electronegativities. (The one with the higher electronegativity is the negative one.)
2. Covalent compounds (Non-metals with non-metals or metalloids)
A. Ignore the charges
B. Format: prefix first element
prefix root of 2nd element -ide
C. prefixes:
mono = one
di = two
tri = three
tetra = four
penta = five
hexa = six
hepta = seven
octa = eight
nano = nine
deca = ten
D. determine the quantity of each element. Name the first element. Name the second element.
Place a prefix in front of each element. Change the ending of the second element to –ide.
E. examples:
As2S3 =diarsenic trisulfide
SO3 = sulfur trioxide
3. Ionic compounds (Metals with non-metals or with polyatomic ions)
NEVER use prefixes for compounds starting with metals
A. Metals with only one charge
1. Metals with non-metals (binary)
a. Format: metal name
root of non-metal name –ide
b. name the metal and change the ending of the non-metal to –ide.
c. examples:
NaCl= sodium chloride
BaCl2 = barium chloride
2. Metals with polyatomic ions
a. Format: metal name polyatomic ion name
b. Write the name of the metal followed by the name of the polyatomic ion (from the yellow
sheet.) Do not change the ending of common ions to “ide”
c. Examples:
CaSO4= calcium sulfate
K2CO3 = potassium carbonate
B. Metals with more than one charge
1. Metals with non-metals (binary)
a. Metal name (charge in Roman numerals) non-metal-ide
b. Determine the charge on the first element and put it in Roman numerals behind the
element. Change the ending on the second element to –ide
c. Examples:
CuCl2 =copper (II) chloride
CuCl= copper (I) chloride
Fe2O3 = iron (III) oxide
2. Metals with polyatomic ion
a. Format: metal name (charge in Roman numerals) polyatomic ion
b. examples:
CuSO4= copper (II) sulfate
Cu2SO4= copper (I) sulfate
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