Question

give two different properties of a hydrate that makes it unsuitable as an unknown

Answer 1

1) The hydrates must be reversible in evolving water and regainig its water moecules.

It has to loose water upon heating and regain water in wet condition.

2) The hydrate has to restore its color

Examples:

CuSO₄.5H₂O_{(deep blue solid)} ----^heat---->    CuSO_{4(ashy white solid)} + 5H₂O(g)

CuSO_{4(ashy white solid)} + H₂O_(l) -----> CuSO_{4(aq) (deep blue solid)}

This is a true solid

If the above two protperties are not shown by a compound then that compund is said to be not suitable for hydrate of unknown

Ex: Glucose on heating deomposes to give water

But i cannot regain its structure as glucose on addition of water