QJEEM03Ch04c9: JEE Main 2003 Chemistry - Class 11 JEEM03Ch04c9 Solution: The solubilities of carbonates decrease down the magnesium…

As we move down the group, the lattice energies of carbonates remain approximately the same. However the hydration energies of the metal cation decreases from $\,\,B{e^{ + + }}\,\,$ to $\,\,B{a^{ + + }},\,$ hence the solubilities of carbonates of the alkaline earth metal decreases down the group mainly due to decreasing hydration energies of the cations from $\,\,B{e^{ + + }}\,\,$ to $\,\,B{a^{ + + }}.$