Question

Define the following terms and give two examples each :-

★ Anhydrous Salt
★ Hydrated Salt
★ Water of crystallisation
★Deliquescent substances
★Hygroscopic Substances
★Efflorescent Salts​

Answer 1

Answer:

1. Anhydrous salt-

A compound in which all water molecules are removed is called Anhydrous salt.

EG- anhydrous copper sulphate(CuSO4­) and anhydrous ferrous sulphate(FeSO4)

2. Hydrated Salt-

A compound with one or more chemically combined water molecule.

EG- Copper sulphate pentahydrate (CuSO4.5H2O) and Ferrous sulphate(FeSO4.7H2O)

3. Water of crystallisation-

Water of crystallization is the amount of water molecules which are present in one formula unit of salt.

EG- Proteins with more than 50% of the water of crystallization and copper sulfate pentahydrate with five molecules of water of crystallization.

4. Deliquescent substance-

The substances which absorb moisture from the atmosphere on exposure to air. By absorbing moisture they may dissolve in the water absorbed and change into solution. Such substances are called deliquescent substances.

EG- Calcium chloride.

5. Hygroscopic substances-

The substances which do not undergo any change in physical state on the absorption of moisture from the atmospheric air. These are called hygroscopic substance.

EG- Calcium oxide, cobalt chloride

6.Effloroscent salts-

The salts which lose water of crystallization either completely of partially on exposure to atmospheric air are called efflorescent substances.

EG- Na2CO3.10H2O loses nine water molecules on exposure to air and the remaining one water molecule on heating.

Answer 2

$\star \cal \: Anhydrous \: Salt$

Anhydrous means without water

Anhydrous salt is only the cation and anion making up the salt. All of these hydrated salts can have the water removed by heating and the physical appearance of the dehydrate or anhydrous form of the salt can be quite different from that of the hydrated salt.

★EXAMPLES ★

1-:Table salt is anhydrous sodium chloride (NaCl).

2-:Gaseous HCl is anhydrous, which differentiates it from hydrochloric acid, a solution of 37 percent HCl in water (w/w).

$\star \cal \ \: Hydrated \: Salt$

A hydrated salt is a crystalline salt molecule that is loosely attached to a certain number of water molecules. Salt is created when an acid's anion and a base's cation are combined to produce an acid-base molecule.