What is the minimum volume of water required to dissolve 1g of calcium sulphate at 298 K? (For calcium sulphate, `K_(sp)` is `9.1 xx 10^(-6)`).

Explanation

For a binary salt
` " "s= sqrt(K_(sp))`
` therefore " For " CaSO_4 ,s= sqrt( 9.1 xx 10 ^(-6)) = 3.0 xx10 ^(-3) " mol " L^(-1)`
` " " = 3.0 xx 10 ^(3) xx 136 = 0.41 gL^(-1)`
` " " ` ( Mol . Mass of `CaSO_4 = 40 + 32 + 64 = 136)`
Thus, a saturated solution of ` CaSO_4` contains of 0.41 g of the salt in 1 L .
Hence , the volume of water required to dissolve 1 g of `CaSO_4 = (1)/(0.41) = 2.44 L`