METALS (using reactivity series)

Seite 1

metals tend to lose electrons to form positive ions

reactivity is related to tendency to form ions

more reactive > greater tendency

K (s) -> K^+ (aq) + e^- VS Mg (s) -> Mg^2+ (aq) + 2e^-

Mg does not react as violently w/ water as compared to K

reactivity of metal vs its compound

K metal most reactive,, compound least reactive

Ag metal least reactive,, compound most reactive

effect of heat on metal carbonates

most decompose when heated strongly to produce metal oxide and CO2

carbonate of less reactive metals decompose MORE EASILY

potassium and dium do not decompose

Seite 2

REDUCTION OF METAL OXIDES

1. metals (C/CO/H2)

carbon can remove oxygen from metallic oxides to produce metal and CO2

unable to remove from highly reactive metals (above zinc,, stable so can only be reduced by passing electricity through them,, electrolysis))

only for metals below aluminium

hydrogen can remove to produce metal and H2O

unable to remove from highly reactive metals (abv iron in series)

2. displacement by more reactive metals

metal higher in RS can displace those below it from its oxides or from aqueous solution

Cu^2+ is blue ,, copper metal is reddish brown

Fe2+ is pale green,, grey solid

Fe^3+ is yellow,,

Ni^2+ is green,, silver (??)

Mn^7+ is purple

Cr^6+ is orange,,

Cr^3+ is green,,

silver metal is black

Group I, II, III are generally colourless