Question

Which of the following carbonates decompose readily? A)Li2CO3

B) Na2CO3

C) K2CO3

D)Rb2CO3

Answer 1

It is (a) because thermal stability of alkali metal carbonates increases down the group

This is because the lattice energy is more for anions and cations of similar size.

Thus when Li2CO3 gets converted to Li2o the lattice energy increases by a great extent.

Thus this conversion is favourable.But this is not so in other cases as the sizes are comparable in other cases.