In order come learn just how to uncover the oxidation number of an atom in a provided compound, that is necessary to discover what oxidation number are. The oxidation number of an atom is a number the represents the total variety of electrons shed or gained through it.

Calculating Oxidation Numbers

An oxidation number deserve to be assigned to a given aspect or link by adhering to the complying with rules.

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Any complimentary element has actually an oxidation number equal to zero.For monoatomic ions, the oxidation number always has the very same value as the network charge equivalent to the ion.Oxygen has an oxidation the -2 in most of the compounds. However, in the case of peroxides, the oxidation number corresponding to oxygen is -1.All alkali steels (group 1 elements) have an oxidation state of +1 in their compounds.All alkaline earth metals (group 2 elements) exhibit an oxidation state that +2 in their compounds.In the compounds made up of two elements, a halogen (group 17 elements) have actually an oxidation variety of -1 assigned come them.In the instance of neutral compounds, the amount of every the oxidation numbers of the constituent atoms totals to zero.When polyatomic ions room considered, the amount of all the oxidation number of the atoms that constitute them amounts to the net charge of the polyatomic ion.

Thus, the oxidation number of an atom in a offered compound can be calculated v the actions mentioned above.

Solved Examples

In stimulate to assist students understand how to find oxidation number, the oxidation states of every individual atom in some instance compounds are identified below.


An illustration explaining exactly how to discover oxidation number of the sulphur atom in a sodium sulfate molecule deserve to be found above.

Hydrochloric acid (HCl)

As every the rules debated above, the oxidation state that a team 17 element (halogen) in a diatomic molecule is -1. The is also discussed that hydrogen constantly exhibits one oxidation variety of +1 unless it is paired through a less electronegative element.Since chlorine is an ext electronegative 보다 hydrogen, an oxidation number of +1 can be assigned to the hydrogen atom in HCl.Therefore, the oxidation number of hydrogen is +1 and also the oxidation of chlorine is -1 in HCl. This values can be showed by including these oxidation numbers. Since the complete is zero, i beg your pardon is the worth of the oxidation number matching to a neutral molecule, the values space verified.

Carbon Dioxide (CO2)

According to the rule to calculate oxidation number, which can be uncovered in the vault subsection, the oxidation variety of oxygen in its compound (excluding peroxides) is -2.Since there space two oxygen atom in carbon dioxide, the complete of the oxidation numbers matching to each oxygen is -4.Since the CO2 molecule is neutral, the carbon atom need to exhibit one oxidation state that +4 (the sum of all the oxidation number in a neutral molecule is zero).Therefore, the oxidation state the oxygen was found to it is in -2 and also the oxidation variety of carbon is +4 in a carbon dioxide molecule.

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Students deserve to understand just how to discover oxidation number through the help of the fixed examples provided above. Come learn an ext about oxidation states and also other related concepts such as oxidizing agents, register v BYJU’S and download the mobile applications on your smartphone.