Oxidation Reduction (Redox) in Chemistry

These flashcards cover key concepts and definitions related to oxidation numbers in redox reactions, assisting students in understanding how to assign oxidation states to different elements and compounds.

Redox

A term used to describe oxidation-reduction reactions, where oxidation is the loss of electrons and reduction is the gain of electrons.

Oxidation Number

A number assigned to an element in a chemical compound that describes its degree of oxidation or reduction.

Elemental State

The oxidation state of an element in its pure, uncombined form is zero.

Oxygen Oxidation State

The oxidation state of oxygen in a compound is typically -2, except in peroxides, where it is -1.

Hydrogen Oxidation State

Hydrogen generally has an oxidation state of +1 when combined with nonmetals, and -1 when in metal hydrides.

Overall Charge

For a neutral compound, the sum of oxidation states must equal zero; for an ion, they must equal the ion's charge.

Group 1 Metals

Elements in group one have an oxidation state of +1.

Group 2 Metals

Elements in group two have an oxidation state of +2.

Halogens Oxidation State

Halogens usually have an oxidation state of -1, but this can vary when forming compounds.

Ammonia Oxidation State Example

In ammonia (NH3), hydrogen contributes +3 and nitrogen must balance this with -3.

Sulphate Ion Example

In the sulfate ion (SO4^2-), with four oxygens at -2 each, sulfur must have an oxidation number of +6 to total -2.