What type of reactions are represented by the following equations ?
(i) CaCO3⟶CaO+CO2
(ii) CaO+H2O⟶Ca(OH)2
(iii) 2FeSO4⟶Fe2O3 + SO2 + SO3
(iv) NH4Cl⟶NH3 + HCl
(v) 2Ca + O2⟶2CaO