# A List of Common Polyatomic Ions With Charges and Oxidation Numbers

URL: https://sciencestruck.com/chemistry/list-of-common-polyatomic-ions-with-charges-oxidation-numbers
Category: Chemistry
Published: 2014-10-10T08:22:00
Updated: 2014-10-10T08:22:00
An ion is an atom or molecule that has acquired an electric charge due to loss or gain of electrons. Thus, a polyatomic ion is an ion that is composed of 2 or more atoms. ScienceStruck lists down some common polyatomic ions with their charges and oxidation numbers.

### Did You Know?

A negatively charged polyatomic ion that has one or more oxygen atoms bonded to another element is known as an oxyanion; for e.g. the sulphate, nitrate, and carbonate ions.

A polyatomic ion is composed of two or more atoms, and it carries a charge that is positive or negative.  
  
When a polyatomic ion takes part in a chemical reaction, its oxidation number plays a significant role. The oxidation number is also known as Oxidation State. It is a number that is either positive, negative, or zero. The oxidation number of an ion indicates the number of electrons that an ion can gain, lose, or share when chemically reacting with another ion (monatomic or polyatomic), atom, compound, or molecule.  
  
The oxidation number of a polyatomic ion is the sum of oxidation numbers of its constituent atoms. It is equal to the charge on the ion.

## Common Polyatomic Ions

**Polyatomic Ion**

**Chemical Symbol**

**Charge**

**Oxidation Number**

Ammonium

NH4+

+1

+1

Phosphonium

PH4+

+1

+1

Hydronium

H3O+

+1

+1

Fluoronium

H2F+

+1

+1

Tropylium

C7H7+

+1

+1

Guanidine

C(NH2)3+

+1

+1

Mercury

Hg22+

+2

+2

Acetate

C2H3O2\-

\-1

\-1

Bicarbonate

HCO3\-

\-1

\-1

Bisulphate

HSO4\-

\-1

\-1

Bisulfite

HSO3\-

\-1

\-1

Bromate

BrO3\-

\-1

\-1

Bromite

BrO2\-

\-1

\-1

Chlorate

ClO3\-

\-1

\-1

Chlorite

ClO2\-

\-1

\-1

Cyanide

CN\-

\-1

\-1

Hydroxide

OH\-

\-1

\-1

Hypobromite

BrO\-

\-1

\-1

Hypochlorite

ClO\-

\-1

\-1

Hypoiodite

IO\-

\-1

\-1

Iodate

IO3\-

\-1

\-1

Iodite

IO2\-

\-1

\-1

Nitrate

NO2\-

\-1

\-1

Nitrite

NO2\-

\-1

\-1

Perbromate

HBrO3\-

\-1

\-1

Perchlorate

ClO4\-

\-1

\-1

Permanganate

MnO4\-

\-1

\-1

Dihydrogen phosphate

H2PO4\-

\-1

\-1

Carbonate

CO32-

\-2

\-2

Chromate

CrO42-

\-2

\-2

Dichromate

Cr2O72-

\-2

\-2

Oxalate

C2O42-

\-2

\-2

Peroxide

O22-

\-2

\-2

Sulfate

SO42-

\-2

\-2

Sulfite

SO32-

\-2

\-2

Thiosulfite

S2O32-

\-2

\-2

Hydrogen phosphate

HPO42-

\-2

\-2

Ferricyanide

Fe(CN)63-

\-3

\-3

Phosphate

PO43-

\-3

\-3

Ferrocyanide

Fe(CN)64-

\-4

\-4