1. In the decomposition of hydrated copper(ii)sulphate

Decomposition is the breakdown of molecules or substances by the use of heat.

Hydrated means it contains water of crystallization.

                       HEAT

CuSO4.H2O                        CuSO4 + H2O

N.B: CuSO4.H2O= hydrated copper(ii)sulphate(blue colour)

CuSO4=copper sulphate

H2O=water

2. Heating copper(ii)carbonate

                  HEAT         

CuCO3                          CuO + CO2

Copper(ii)carbonate         copper(ii)oxide + carbon dioxide

3. Heating of sugar

                      HEAT

C6H12O6                          6C + 6H2O

SUGAR                                   carbon + water

4. Burning phosphorus in oxygen

                   HEAT

P4 + O2                        2P2O

5. Burning of magnesium

                        HEAT

2Mg + O2                          2MgO

6. Reaction with some metals

Ca + 2H2O                         Ca(OH)2 + H2