Question

Salt cake is
A) Sodium sulphate
B) Sodium chloride
C) Sodium Bisulphite
D) Sodium sulphate and sodium chloride

Answer 1

Hint: Salt cake is an impure form of metal sulphate. It is obtained by the reaction of sulphuric acid on the common salt during the synthesis of hydrochloric acid. This metal sulphate has applications in the manufacturing of glass, soaps, ceramic glaze, etc.

Complete answer:
Sodium sulphate or the sulphate of soda is an inorganic compound. It has a general chemical formula as $\text{ N}{{\text{a}}_{\text{2}}}\text{S}{{\text{O}}_{\text{4 }}}$ . It is highly soluble in water.
Sodium sulphate is also known as the salt cake. It is prepared by the reaction of sodium chloride with sulphuric acid. The reaction of the generation of sodium sulphate is as shown below,
$\text{ 2NaCl + }{{\text{H}}_{\text{2}}}\text{S}{{\text{O}}_{\text{4}}}\to \text{ N}{{\text{a}}_{\text{2}}}\text{S}{{\text{O}}_{\text{4}}}\text{ + 2HCl }$
The impure form of sodium sulphate which is obtained by the reaction of sulphuric acid with the common salt in the synthesis of hydrochloric acid is known as the ‘salt cake’. Sodium sulphate has various applications in the manufacturing of glass, ceramic glaze, soaps, etc.
The salt cake is an anhydrous sodium sulphate. The salt cake can also be obtained by the reaction of soda ash with sulphur and used in the sulphate process.
Thus salt cake is sodium sulphate.

Hence, (A) is the correct option.

Note: Note that the decahydrate form of sodium sulphate is known as the Glauber salt. Glauber salt is a disodium sulphate decahydrate. Its general formula is given as $\text{ N}{{\text{a}}_{\text{2}}}\text{S}{{\text{O}}_{\text{4}}}\text{.10}{{\text{H}}_{\text{2}}}\text{O }$ .the various hydrated form of sulphate salt have different common names. Always remember the common names for compounds.