Which is more soluble among the follwing

In general in all IA group and IIA group compounds except fluorides and hydroxides solutility down the group decreases but the two exceptions are carabonates & bicarbonates of IA group where solubility increases down the group. Generally in a series of compound with increase the size of oppositely charged ion the lattice energy decreasesIn case of smaller size anion like F- ,OH- ,O-2  with small change in cation size , there is a considerable change in lattice energy and hence in this case the solubility depends only on the lattice energy but  not on hydration energyAs lattice energy decreases from BeO to BaO, solubility increases from BeO to BaO .Therefore, BaO is most soluble where as BeO is least soluble