Page 2 - Microsoft Word - Module-4

Halides:

 All are ionic except BeX which is covalent and
2

soluble in organic solvent.

 BeCl has chain structure in solid state.
2

 In vapour phase BeCl tends to form a chloro-bridged
2
dimer.

Salts of oxoacids: -

(a)Carbonates:

 Carbonates of Alkaline earth metals are insoluble in

water and solubility decreases down the group due

to more increase in lattice energy than hydration

energy.

 Thermal stability of carbonates increases down the

group.

(b)Sulphates:

 Sulphates of alkaline earth metals are all white solids

and stable to heat.

 BeSO and MgSO are readily soluble in water
4
4
2+
2+
because hydration enthalpy of Be and Mg
overcome lattice enthalpy.