What is the smallest entity of a hydrate (e.g. CuSO4 • 5H2O)? (A formula unit?)

1 Answer
Feb 2, 2017

The smallest entity of an hydrate is surely the given formula unit:



Copper sulfate is a white powder. It may be recrystallized from water to give the pentahydrate, which has a truly beautiful blue colour. Macroscopic crystals of the hydrate may be grown, and the formula of this material corresponds to the given #"pentahydrate"#.