Discuss on : (i) Carbonates.

Explanation

(i) carbonates:
Alkaline earth metal forms `MCO_3` type carbonates
These carbonates are insoluble in water
The solubility of these carbonates in water decreases as the atomic no. of the element increases
The thermal stability increases with increasing cationic size.
These carbonates decompose on heating to give `CO_2`
`CaCO_3 overset(Delta) to CaO+CO_2`
`BeCO_3` is unstable and kept only in at atmosphere of `CO_2`
(ii) Sulphates:
Alkaline earth metals forms `MSO_4` type sulphates
These are white solids and are stable to heat.
`BeSO_4 and MgSO_4` are readily soluble in water due to high hydration enthalpies of `Be^(2+), Mg^(2+)`
The solubility decrease from `CaSO_4` to `BaSO_4`
(iii) Nitrates:
ALkaline earth metals forms `M(NO_3)_2` type nitrates.
These are formed by the reaction of carbonates in dil. `HNO_3`
`Mg(NO_3)_2` crystallises with six water molecules and `Ba(NO_3)_2` is an hydrous.
All of these decompose on heating to give the respective oxides.
`2M (NO_3)_2 to 2MO +4NO_2 +O_2`
`M=Be, Mg,Ca,Sr,Ba`