redox reactions

what are alkalis?

bases that dissolve in water

what are bases?

substances that neutralise acids - producing a salt

what is a redox reaction?

a reaction where oxidation and reduction have both taken place

what are spectator ions?

ions that do not change in a reaction

what is the oxidation number of Mg and O in the compound MgO?

M = +2 as it has lost two electrons

O = -2 as it has gained two electrons

what is the oxidation number of F

always -1

what are the oxidation numbers for O?

-2 usually

-1 in peroxides

+2 when reacted with flourine

what are the oxidation numbers for halogens?

-1 usually

+1 possibly if reacted with flourine or oxygen

what are the oxidation numbers of H?

+1 usually

-1 in metal hydrides e.g LiH