8.8 redox reaction

what is a redox reaction

when electrons are transferred between substances at the same time

displacement reactions and redox

displacement reactions are a type of redox,

metal ion always gains electrons and is reduced

metal atoms always lose electrons and get oxidised

 displacement reactions and redox

zinc + copper sulfate =zinc sulfate +copper

Zn (s) +CuSo(2)(s) =ZnSo(4)(aq) +Cu(s)

zinc loses 2 electrons to become 2+ ion -is oxidised zinc is more reactive then copper,electrons (2e-) stay at metal surface

copper ions gain those electrons-Cu2+ ions in solution take electrons that zinc released,the copper ions are reduced(they gain electrons) and become solid copper metal forming redish layer on zinc strip

what do ionic equations show 

only the particles that react and the particles they form 

what do ionic equations for redox concentrate on

substances which are oxidised or reduced

ionic equations of displacement reactions

chloride ions dont change in the reaction and so can be ignord

Fe(s) + 2HCI(aq) =FeCL(2)(aq) + H(2)(g)

iron and hydrochloric acid react to form iron chloride and hydrogen

Fe(s) + 2H(+)(aq) =Fe(2+)(aq) +H(2)(g)

iron atoms oxidised to lose two electrons and to Fe(2+) and H(+) ions reduced to hydrogen