Chemical changes - Oxidation, reduction, redox

a reaction that involves gaining oxygen, can also involve losing electrons

a reaction where oxygen is lost,can also be when electrons are gained

oxidation is loss ( of electrons ) reduction is gain

2Mg + O2 – 2MgO magnesium is oxidised to make magnesium oxide

2CuO + C – 2Cu + CO2 copper oxide is reduced to copper

by reduction using carbon - in the reaction, the ore is reduced as oxygen is removed from it and carbon gains oxygen so is oxidised

using electrolysis

a reaction where oxidation and reduction happen at the same time, also when electrons are transferred

displacement reactions, where a more reactive metal displaces a less reactive one in a compound • for example iron + copper sulfate – iron sulfate + copper • the iron loses 2 electrons, becomes a 2+ ion and is oxidised • copper gains 2 electrons to become a copper atom, it’s reduced

• less reactive metal is reduced • more reactive metal is oxidised

an equation which only shows the particles that react and the products they form

ions that don’t change during the reaction and can be crossed out in an ionic equation

because it’s cheap and abundant