NAMIMG ACIDS
First, know when you have an acid – Always start with H! *Look for this first when naming.
There are 2 types of acids: Oxy acids and Binary acids
1) OXY ACIDS - They have “H” with a polyatomic ion (like SO42-) -> crisscross with H+ to get H2SO4
a) If the polyatomic ion bound to the H ends in –ate change the acid ending to –ic (see examples below).
Example 1 - H2SO4
Example 2 - H3PO4
Example 3 - carbonic acid
Sulphate -> sulphuric acid
phosphate-> phosphoric acid
H2CO3
b) If the polyatomic ion bound to the H ends in –ite change the acid ending to –ous (see examples below).
Example 1 - H2SO3
Example 2 - H3PO3
Sulphite -> sulphurous acid
Example 3 - carbonous acid
phosphite-> phosphorous acid
H2CO2
2) BINARY ACIDS - contain only hydrogen and one other element, e.g. HF.
Rules
1. Use hydro as the prefix.
2. Then add the stem name of the second element.
3. Add an ic ending
Formula
Name of Acid
HCl (aq)
Hydrochloric acid
H2S (aq)
Hydrosulphuric acid
HF (aq)
Hydrofluoric acid
For all acids, the number of H atoms is equal to the charge on the ion it is bonding with (crisscross).
Practice makes Perfect 
Formula
HF
Name
hydroiodic acid
H3P
sulphuric acid
chloric acid
HNO3
H2CO3
hydrosulphuric acid
HClO3
Naming BASES – Contain hydroxide (OH-) ions
- same as for any other polyatomic ion but you should know that if it has a hydroxide group, it is a BASE!
Examples
Name
Sodium hydroxide
Formula
NaOH
Calcium hydroxide
Ca(OH)2
iron (III) hydroxide
Fe(OH)3
Practice, Practice Practice
Name
Formula
aluminum hydroxide
Cu(OH)2
RbOH
Barium hydroxide
NAMING AND FORMULAS: MOLECULAR COMPOUNDS
-
Molecular compounds form between 2 NONMETALS (they will both have a negative charge).
-
Naming molecular compounds is different from ionic/polyatomic compounds because a prefix is used to
indicate the number of each atom present for each element
You need to memorize the following prefixes:
1
mono
-
2
Di
3
Tri
4
5
6
7
Tetra
Penta
Hexa
Hepta
8
9
Octa
Nona
10
Deca
Note: do not use “mono” for the first element
Example 1 - sulphur trioxide
Example 2 - diphosphorus pentasulphide
SO3
P2S5
Practice Questions
carbon dioxide ____________________
phosphorus trichloride ___________________
sulphur hexaflouride _______________
nitrogen monoxide _____________________
Naming Molecular Compounds: Example 1 - N2O
Example 2 – BrI
=
___________________
=
dinitrogen monoxide
Example 3 - XeF4
=
___________________
Practice Questions
1. N2O4 __________________________
4. SO2 ______________________________
2. H2O ___________________________
5. P2O5 _____________________________
3. CF4 ___________________________
6. NCl3 _____________________________