(i) Formation of Oxides : BeO, MgO, CaO, SrO, BaO
Oxides of alkaline earth metals are obtained by heating the metal in di-oxygen or decomposition of their carbonates.
2M + O2 → 2MO
MCO3 → MO + CO2
(M = Be, Mg, Ca)
Properties:
1. The oxides have high melting point and have low vapour pressure.
2. The enthalpies of formation of these oxides are quite high and are very stable.
3. Except BeO, all other oxides of alkaline earth metals are basic in nature. BeO is amphoteric.
4. The solubility, thermal stability and basic character of these oxides increase with increasing atomic number.
