Nomenclature Rules

Binary covalent compounds:

Named in the order they appear in the formula. 

 

Prefix-__________  prefix_______ide

Prefix	Number
mono-	1
di-	2
tri-	3
tetra-	4
penta-	5
hexa-	6
hepta-	7
octa-	8
nona-	9
deca-	10

Binary ionic compounds:
The metal is always named first.

Metals ions with a fixed charge:

      _________  _______ide

Metal	Charge
IA metals	+1
Silver (Ag)	+1
IIA metals	+2
Zinc (Zn)	+2
Cadmium (Cd)	+2
Aluminum (Al)	+3
Gallium	+3

 

 

 

 

 

 

 

Metal ions with variable charge:

_________ (X) ________ide

(where X = charge written as a Roman numeral)

Ionic Compounds with Polyatomic ions

Ammonia:

When NH₄⁺ is at the beginning of the formula, the compound is named:

ammounium ______.

Oxyanions:

Step 1: 

You need to memorize the following.  These “-ate” ions are the “basic” unit for the polyatomic anions.

Borate = BO₃^3-

Carbonate = CO₃^2-

Nitrate = NO₃^-

Phosphate = PO₄^3-

Arsenate = AsO₄^3-

Sulfate = SO₄^2-

Selenate = SeO₄^2-

Tellurate = TeO₄^2-

Chlorate = ClO₃^-

Bromate = BrO₃^-

Iodate = IO₃^-

 

Step 2:

If the oxyanion has two less O than the “-ate” ion, hypo_____ite.

If the oxyanion has one less O than the “-ate” ion, _______ite.

If the oxyanion has one more O than the “-ate” ion, per______ate

Step 3:

If the oxyanion has one hydrogen, the charge increases by +1, and the name of the ion is hydrogen________.

If the oxyanion has two hydrogens, the charge increases by +2, and the name of the ion is dihydrogen________.

 

Other polyatomic ions:

These polyatomic ions are not modified by prefixes or suffixes and must be memorized:

Hydroxide = OH^-

Cyanide = CN^-

SCN^- = thiocyanate

MnO₄^- = permanganate

C₂H₃O₂^- = acetate

O₂^2- = peroxide

C₂O₄^2- = oxalate

CrO₄^2- = chromate

Cr₂O₇^2- = dichromate

Acids

Binary acids:

Hydro______ic acid

 

Oxyacids:

For the oxyacids, the “basic” name is _______ic acid.

If the oxyacid has two less O than the “-ate” ion, hypo_____ous acid

If the oxyacid has one less O than the “-ate” ion, _______ous acid

If the oxyacid has one more O than the “-ate” ion, per______ic acid