Oxidation, reduction and Redox equations

What is oxidation

The loss of electrons or the gain of oxygen

What is reduction

the gain of electrons or the loss of oxygen

What is a disproportionation reaction

This is where a single substance is both oxidised and reduced

What is a redox reaction

This is where both oxidation and reduction occurs in a single reaction

What is the oxidation state of an element

The oxidation state is the number of electrons which must be added to a positive ion or the number of electrons which must be removed from a negative ion to give a neutral atom

What is the oxidation state for an uncombined element (Mg, H2,O2 etc)

0

What is the oxidation state for oxygen in general compounds and then in peroxides

General compounds ( MgO) O = -2

Peroxides (H2O2) O = -1

What is the oxidation state of hydrogen in compounds then in metal hydrides

In compounds (HCl) H = +1

In metal hydrides (NaH) H= -1

What is the oxidation states of group 1 metals and group 2 metals?

In group 1 metals (KCl) the metal in the compound (K) is always + 1

In group 2 metals (CaF) the metal in the compound (Ca) is always +2

What are the oxidation states of group 7 elements in compounds and in compounds where they are combined with a more electronegative element

In compounds (MgF2) F = -1

In compounds with a more electronegative element ( NaClO ) F = +1, Na = +1 O = -2

What are oxidising agents

These are substances which oxidise another substance and so are electron acceptors ( They themselves are reduced)

What are reducing agents?

These are substances which reduce another substance and so are electron donors ( they themselves are oxidised)

Steps for constructing half equations for redox reactions

example for constructing half equations for redox reactions

Combinding 2 half equations for an overall equation example