Calcium nitrate has a measured Ksp=3.2 at 25∘C. How should this compound be classified with respect to its solubility in water under these conditions?
a) Sparingly soluble, because its Ksp is close to 1
b) Practically insoluble, since its Ksp is well below that of typical soluble salts
c) Soluble, because its equilibrium constant is significantly greater than 1
d) Indeterminate without additional thermodynamic data such as lattice enthalpy