1. Naming the Inorganic Compounds
Kavita Gupta

2. Classification of Compounds for Naming Purposes
Ionic compounds
Formed by a metal and a nonmetal or a polyatomic ion
Generally solids in the natural state
Ex: NaCl, K2SO4, PbCO3, ZnS, KMnO4
Molecular Compounds
Made up exclusively of nonmetals
Generally liquids or gases in natural state
Ex: NO2, CO2, P2O5, H2O
Acids
Begin with a H
Generally present as aqueous solutions or gases
HCl, HClO4, H2CO3, HNO3, HC2H3O2, HCOOH

4. Naming the Ionic Compounds
Ionic Compounds- made of a cation (either from group 1, group 2 or transition metals) and an anion (monoatomic or polyatomic anion)
Anions are named the same for any ionic compounds. Monoatomic anion ends in –ide and polyatomic anion is named just like the name of the polyatomic anion.
Cation from Transition Metal
Old Way of Naming: Lower of the two charges cation name ends in –ous and higher of the two charges cation name ends in –ic.
Stock Way:Name the cation as its element, followed by its oxiation number (Charge) within parenthesis.
Cation from Group 1 (alkali metal) or Group 2 (alkaline earth)
Name the cation as the element.

5. Practice on Naming Ionic Compounds
Na2SO4
KClO4
Ionic Compounds with Cations from Group 1 and 2
PbS
Cu(NO3)2
Ionic Compounds with cations from transition metals

6. Sodium Sulfide Potassium Nitrate Ferrous Sulfate Ammonium Carbonate
Criss Cross Method for writing the formula for an ionic compound given its name
Criss-cross method involves bringing the valency (charge) of one element down as a subscript next to the other element or polyatomic ion.
Practice writing the formula of the following compounds by using the criss-cross method.
Sodium Sulfide
Potassium Nitrate
Ferrous Sulfate
Ammonium Carbonate
Cupric Nitride

7. Naming the Molecular Compounds
There are two ways of naming the molecular compounds
Prefix Way
Use prefixes mone-, di-, tri- etc. to indicate number of atoms of each element. Do not use mono before the first element.
Ex. N2O5- Di nitrogen Pentoxide
CO2- Carbon Dioxide
Stock Way
Write name of the first element followed by its oxidation state in parenthesis
Ex: N2O5–
Nitrogen (V) Oxice
CO2- Carbon (IV) Oxide
CO – Carbon (II) Oxide

8. Naming the Acids
To name an acid, first check to see if it is an oxy acid or not. Presence of Oxygen in the chemical formula of an acid indicates an oxyacid. Ex. HCl is not an oxyacid but HClO4 is an oxyacid.
Oxyacids: Anion ending decides the name of the acid. If anion ends in –ate, then acid is –ic acid, if anion ends in –its, then acid is –ous acid.
Ex. HClO4 Perchloric Acid (anion perchlorate)
Ex. HClO3 Chloric Acid (anion Chlorate)
To name an acid without oxygen, start naming with Hydro-followed by the name of anion ending in –ic Acid.
Ex. Ex. HCl Hydrochloric acid

9. Naming of Complex Compounds
Name cation first followed by anion. Within a complex, transition metal is named first with its charge listed within parenthesis, followed by ligands and then anion. If complex is anion, then its name ends in –ate.
Please go back to Ch 2 in the ibook for details on the naming of the complexes or coordination compounds.

10. Naming of the Hydrates
Hydrates are ionic compounds that have loosely attached water molecules to them. Ex. CuSO4. 5H2O.
To name the hydrates, name the ionic compound first and then use the prefix that indicates the number of water molecules attached.
Ex. The name of CuSO4.5H2O is Cupric Sulfate pentahydrate or Copper (II) Sulfate pentahydrate.

11. Common Cations with Variable Valency
Cuprous, Cupric
Copper Cu
Cu +
Cu 2+
Cobaltous, Cobatic
Cobalt Co
Co 2+
Co 3+
Ferrous, Ferric
Iron Fe
Fe 2+
Fe 3+
Plumbous, Plumbic
Lead Pb
Pb 2+
Pb 4+
Mercurous, Mercuric
Mercury Hg
Hg2 2+
Hg 2+
Stannous, Stannic
Tin Sn
Sn 2+
Sn 4+

12. Common Polyatomic Ions
Ammonium
NH4 +
Chlorate
ClO3 -
Thiosulfate
S2O3 2-
Nitrate
NO3 -
Perchlorate
ClO4 -
Thiocynate
SCN -
Phosphate
PO4 3-
Chlorite
ClO2 -
Peroxide
O2 2-
Hydroxide
OH -
Hypochlorite
ClO -
Sulfite
SO3 2-
Sulfate
SO4 2-
Permanganate
MnO4 -
Nitrite
NO2 -
Carbonate
CO3 2-
Acetate
C2H3O2 -
CH3COO -
Phosphite
PO3 3-
Chromate
CrO4 2-
Bicarbonate (hydrogen carbonate)
HCO3 -
Bisulfate (hydrogen sulfate)
HSO4 -
Dichromate
Cr2O7 2-
Cyanide
CN -
Oxide
O 2-