Question

What is water of crystallization? Explain with a suitable example.

Answer 1

Crystallization is basically a technique which is used for the purification of substances or we can say that a special technique to separate solids from a solution. This technique is mainly used in the purification of seawater.

Complete answer:
Crystallization can also be defined as a process through which the atoms or molecules arrange themselves within a substance or in a well-defined three dimensional lattice so that it can minimize the overall energy of an atom. When any substance goes through the process of crystallization then its atoms or molecules bind together through well-defined angles.
Crystallization process is mainly done in an open container in which the solvent molecules start evaporating and the solute particles left behind the solution. When the solution cools down the crystals of the solute start accumulating on the surface which are known to be crystals that can be easily collected and dried.
Water of crystallization gives us the information about the water molecules present in one formula unit of a salt. This can be easily explained on the basis of example hydrated copper sulphate whose chemical formula is $CuS{{O}_{4}}.5{{H}_{2}}O$, in this we can mention that copper sulphate has five water molecules or five water of crystallization.

Note:
There is no definite size for crystals but it actually depends upon the cooling rate of the solution i.e. if the solution is cooled at very fast rate then many tiny crystals were formed in the reaction and if solution is cooled slowly then large crystals are formed.