6 For each pair determine which compound is likely to be mor

6. For each pair determine which compound is likely to be more soluble in water and explain your reasoning. a) CaSO4 or BaSO4 b) MgS or SrS

Solution

a)CaSO4 (calcium sulfate) is more soluble in water than BaSO4 (barium sulfate), because it has more hydration enthalpy and smaller in size than barium sulfate.(hydration enthalpy decreases down the group as size increases down the group from Be2+ to Ba2+).Calcium sulfate has more hydration enthalpy means it can adhere more no. of water.So calcium sulfate is more soluble than barium sulfate.

b).MgS is more soluble in water than SrS, because it has more hydration enthalpy and smaller in size than SrS.