Question

Why is $ BeS{O_4} $ water soluble and $ CaS{O_4} $ not?

Answer 1

Hint :The inorganic compound barium sulphate has the chemical formula BaSO4. It is a crystalline white substance that is odourless and water insoluble. Almost all of the barium used in industry comes from barite, which is frequently impure
Almost all of the barium used in industry comes from barite, which is frequently impure. Thermo-chemical sulphate reduction (TSR), also known as carbothermal reduction (heating with coke), is used to convert barite into barium sulphide:

Complete Step By Step Answer:
Almost all of the barium used in industry comes from barite, which is frequently impure. Thermo-chemical sulphate reduction (TSR), also known as carbothermal reduction (heating with coke), is used to convert barite into barium sulphide:
 $ BaS{O_4} + 4C \to BaS + 4CO $
Calcium sulphate and its hydrates are inorganic compounds with the formula CaSO4. It is utilised as a desiccant in the form of -anhydrite. One hydrate is known as plaster of Paris, whereas another is found in nature as the mineral gypsum.
The alkaline earth metal sulphates' solubility decreases as they progress through the group. CaSO4 is insoluble in water, whereas BeSO4 is soluble. This is because $ B{e^{2 + }} $ ions' higher hydration enthalpies surpass the lattice enthalpy factor, allowing their sulphates to dissolve in water. The rest of the compounds' hydration enthalpies do not match the lattice enthalpy factor, making these sulphates insoluble in water.

Note :
Solubility is determined by the number of solute molecules that can be present in a volume of solution before they begin to preferentially associate with each other over the solvent molecules. When the solute molecules are distributed, the interactions between the solvent and solute molecules replace the bonds or attractions that hold the particles together in the solute.