Naming ionic formulae

When naming an ionic compound follow the the steps outlined below.

Step 1- identify the ions present in the compound.
Step 2 - place the positive ion first followed by the negative ion. If the ion has more than one charge, eg Fe2+ or Fe3+ indicate the charge by using brackets and Roman numerals. Iron(II) or Iron(III).
Step 3 - if a cation, usually a transition metal, has more than one possible charge, eg Fe2+ or Fe3+ the exact charge of the cation is shown using Roman numerals; in this case Fe3+ is written as Fe(III).
An example is iron oxide with the following formula Fe2O3; it would be written as "Iron (III) oxide".



Example 1- What is the name of the compound with the following formula (NH4)3PO4

Step 1- identify the ions present . (The ions present are (NH4+) ammonium and (PO4-3) phosphate
Step 2 - place the positive ion first followed by the negative ion. Ammonium phosphate
Step 3 - this step is not needed.

Example 2- What is the name of the compound with the following formula MnO2

Step 1- identify the ions present . (The ions present are Manganese and oxide
Step 2 and 3 - place the positive ion first followed by the negative ion. Manganese(IV) oxide
Charge of 1+
Charge of 2+
Charge of 3+
Ammonium(NH4+)
Magnesium(Mg2+)
Aluminium(Al3+)
Hydrogen(H+)
Calcium(Ca2+)
Chromium(Cr3+)
Lithium(Li+)
Barium(Ba2+)
Iron(III)(Fe3+)
Sodium(Na+)
Zinc(Zn2+)
Potassium(K+)
Copper(II)(Cu2+)
Silver(Ag+)
Mercury(Hg2+)
Copper(Cu+)
Iron(II)(Fe2+)
Nickel(Ni2+)
Tin(II)(Sn2+)
Lead(II)(Pb2+)
Charge of 1-
Charge of 2-
Charge of 3-
Hydroxide(OH-)
Oxide(O2-)
Nitride(N3-)
Hydrogen sulfide(HS-)
Sulfide(S2-)
Phosphate(PO43-)
Nitrite(NO2-)
Sulfate(SO42-)
Nitrate(NO3-)
Sulfite(SO32-)
Acetate(CH3COO-)
Carbonate(CO32-)
Fluoride(F-)
Dichromate(Cr2O72-)
Chloride(Cl-)
Bromide(Br-))
Iodide(I-)
Permanganate(MnO4-)

On the left is a table of some of the more common ions and their charge.

Write the name of the following compounds.

1) ZnSO4

2) Al2(SO4)3

3) Ag2Cr2O7

4) FeSO4

5) PbSO4

6) Fe2(SO4)3

7) K2CO3

8) Cu(OH)2

9) Na2CO3

10) Al2S3

11) NaHS

12) Fe2(SO3)3

Click for solutions

Click for more exercises