The chemical formula of plaster of Paris is: MCQ with Answer and Explanation

Explanation:
Plaster of Paris (CaSO₄·½H₂O) reacts with water to form gypsum (CaSO₄·2H₂O) which sets into a hard solid mass with slight expansion. Reaction: CaSO₄·½H₂O + 1½H₂O → CaSO₄·2H₂O. This property is used for casting and setting broken bones.

Explanation:
Portland cement primarily consists of calcium silicates (C₃S and C₂S) along with aluminates. These are formed by heating limestone and clay.

Explanation:
Sulphuric acid is a key reagent in many processes: to produce HCl from NaCl, HNO₃ from nitre, fertilizers (superphosphate), and in petroleum refining, pickling, etc. It is also used as a dehydrating agent and catalyst. Ammonia is made by Haber process without H₂SO₄. NaOH is made by electrolysis of brine. H₂SO₄ is known as 'king of chemicals'.