Redox Reactions and Oxidation Numbers

Acid-base reactions

Precipitation reactions

Redox reactions

Combustion reactions

The loss of electrons by a substance.

The gain of electrons by a substance.

The decrease in mass of a substance.

The formation of a lighter compound.

LEO GER (Loss of Electron is Oxidation, Gain of Electron is Reduction)

OIL RIG (Oxidation Is Loss, Reduction Is Gain)

RED OX (Reduction is Oxidation)

GER LEO (Gain of Electron is Reduction, Loss of Electron is Oxidation)

+1

-1

0

Varies depending on the element

Equal to the charge of the most electronegative atom.

Always positive.

Always zero.

Dependent on the number of atoms in the compound.

Zero.

The charge of the ion.

The sum of the oxidation numbers of the most electronegative and least electronegative atoms.

A positive integer.

Nitrogen is oxidized, hydrogen is reduced.

Nitrogen is reduced, hydrogen is oxidized.

Both nitrogen and hydrogen are oxidized.

Both nitrogen and hydrogen are reduced.

To simplify the calculation of individual atom oxidation states.

To ensure the conservation of mass for each element.

To separately balance the electron transfer for oxidation and reduction processes.

To determine the overall charge of the reactants and products.