Question

1. Water of crystallization present in aluminum sulphate are
a.24
b. 18
c. 6
d. 1
2. Shape of potash alum crystal is
a. moloclinic
b. octahedral
c. cubic
d. hexagonal
3. Potash alum is
a. double salt
b. coordination complex
c. 3D complex compound
d. inorganic base
4. Dilute sulphuric acid is added during preparation of potash alum to
a. prevent hydrolysis of aluminum sulphate
b. prevent hydrolysis of potassium sulphate
c. prevent oxidation of potassium sulphate
d. dissolve both the salts K,SO, and Al(SO )3.
5. The process occurs when crystals of potash alum is heated?
a. burns the crystals
b. the crystal melts
c. looses the water of crystallization
d. no change occurs in crystal​

Answer 1

In chemistry, water(s) of crystallization or water(s) of hydration are water molecules that are present inside crystals. Water is often incorporated in the formation of crystals from aqueous solutions.[1] In some contexts, water of crystallization is the total mass of water in a substance at a given temperature and is mostly present in a definite (stoichiometric) ratio. Classically, "water of crystallization" refers to water that is found in the crystalline framework of a metal complex or a salt, which is not directly bonded to the metal cation.

Upon crystallization from water or moist solvents, many compounds incorporate water molecules in their crystalline frameworks. Water of crystallization can generally be removed by heating a sample but the crystalline properties are often lost. For example, in the case of sodium chloride, the dihydrate is unstable at room temperature.

Coordination sphere of Na+ in the metastable dihydrate of sodium chloride (red = oxygen, violet = Na+, green = Cl−, H atoms omitted).[2]

Compared to inorganic salts, proteins crystallize with large amounts of water in the crystal lattice. A water content of 50% is not uncommon for proteins.