Post on 21-Jun-2018
Naming• There are almost an infinite number of ways in
which element can combine in order to make
compounds
• Therefore, a systematic method is used so that we
can easily name all compounds
• We will focus on naming inorganic (all non-carbon
containing) compounds in this lecture
Names and Formulas of Ionic Compounds:
Cations1. Cations formed from metal atoms have the same name
as the metal
o E.g.: Na+ is a sodium ion, Zn+2 is a zinc ion, etc.
2. If a metal can have multiple charges, the positive charge
is indicated by a Roman numeral in parentheses
following the name of the metal.
o E.g.: Fe2+ = iron (II) ion, Cu+3 = copper (III) ion
o Iron, cobalt, copper, tin, and lead are the most
common metals that have multiple charges
Names and Formulas of Ionic Compounds: Anions1. The names of elements that are anions are formed
by adding –ide to the end of the name
o Cl- = Chloride ion
o Br- = Bromide ion
o O2- = Oxide ion
Names and Formulas of Ionic Compounds: Anions2. Polyatomic ions that contain oxygen have names
ending in either –ate or –ite
NO3- = Nitrate
NO2
- =Nitrite
SO42- = Sulfate
SO3
2- = Sulfite
-ate ending polyatomic have more oxygens
than –ite ones!
Names and Formulas of Ionic Compounds: Anions• Sometimes oxygen binds to the same ion with
increasing amount of oxygens (e.g. ClO4-, ClO3
-,
etc.)
• These come in 4’s and the pattern is always:
o Per_____ate = 4 oxygens
o _______ate = 3 oxygens
o _______ite = 2 oxygens
o Hypo______ite = 1 oxygen
• Example:
o ClO4- = Perchlorate, ClO3
- = Chlorate, ClO2- =
Chlorite, ClO- = Hypochlorite
Names and Formulas of Ionic Compounds: Anions3. Anions derived by adding H+ to an oxygen
containing anions have the prefix of hydrogen or
dihydrogen based on the number of H+ in the anion
Names and Formulas for Acids
• Recall, acids are compounds that donate a
hydrogen ion to solution.
• Acids are named differently than other compounds
• Two rules when naming acids:
1. Acids containing anions that are only single
elements are named by changing the –ide
prefix on the anion to –ic and adding hydro in
front of the anion and then adding acid at the
end.
• E.g. HCl is hydrochloric acid
2. Acids containing polyatomic ions are named by
changing –ate to –ic and –ite to –ous on the
anion and then adding acid at the end
Naming Covalent Molecules (Non-Acids)
• The process for naming covalent inorganic
compounds requires the following rules:
1. The name of the element furthest
left on the Periodic Table is written
first
2. If both elements are in the same
group, the larger one is written 1st
3. The name of the second element
is given an –ide ending
4. Greek prefixes are used to show
the number of atoms
Prefix Meaning
Mono- 1
Di- 2
Tri- 3
Tetra- 4
Penta- 5
Hexa- 6
Hepta- 7
Octa- 8
Nona- 9
Deca- 10
Naming Compounds Flow Chart
Does the Formula begin with H
NO YES
Does it begin with a metal which has more than
one oxidation number? (e.g.; Fe, Ni, Cu, Sn, Hg)
NO YES
Name the first element
followed by its oxidation number (Roman numeral)
Does the formula contain a polyatomic ion?
NO YES
Are both elements nonmetals?
NO YES
Name the first element, Then the second element
With the –ide ending.
Name the first element
using the proper prefix. (never mono-). Name the
second element with the proper prefix (including
mono- and –ide ending. 1 mono-
2 di- 3 tr-
4 tetra- 5 penta-
6 hexa- 7 hepta-
8 octa- 9 nano-
10 deca-
Name the first element, then the polyatomic ion. If two elements
are present, name both, then the polyatomic ion. (e.g.; NaHCO3
Is sodium hydrogen carbonate)
It is an Acid (must be aqueous)
Does the acid contain a polyatomic ion?
YES NO
Ending of polyatomic ion
-ate -ite
Name the polyatomic
ion, replacing the –ate
ending with –ic. Add the word acid.
Name the polyatomic
ion, replacing the –ite ending with –ous. Add the word acid.
Write the prefix hydro,
then the name of the
second element with –ic ending. Add the word acid.