A. Calcium oxide or Quick lime (CaO)

↪ It is white amorphous porous solid.
↪ It melts at 2570°C.
↪ It produces lime light (dazzling light) when heated in oxy-hydrogen flame.
↪ Molecular formula: CaO
↪ Chemical name: Calcium oxide
↪ Common names: Quick lime, burnt lime, common lime or caustic lime
↪ Commercially it is prepared by the calcination of lime stone or chalk in lime kiln at 800-1000°C with evolution of CO₂ gas which goes away.

⁕ Uses of Quick lime

↪ It is used as a chief constituent of cement.
↪ It is used in the manufacture of glass, bleaching powder etc.
↪ It is used as refractory material.
↪ It is used as basic flux in the metallurgy.
↪ It is used as drying agent.
↪ It is used in softening hard water.
↪ It is used in soda lime.
↪ It is used as a disinfectant and germicide

B. Bleaching Powder (CaOCl₂)

↪ Molecular Formula: CaOCl₂
↪ Chemical name: Calcium chloride hypo-chloride
↪ Common name: Bleaching Powder

⁕ Uses of Bleaching Powder

↪ It is used for bleaching agent in textile industries.
↪ It is used in manufacture of chloroform.
↪ It is used as oxidizing agent.
↪ It is used as a disinfectant and germicide for purification drinking water.

C. Plaster of Paris (2CaSO₄.H₂O)

↪ It is white amorphous powder insoluble in water.
↪ Molecular formula: 2CaSO₄.H₂O or CaSO₄.½H₂O
↪ Chemical name: Calcium Sulphate
↪ Common name: Plaster of Paris

⁕ Uses of Plaster of Paris

↪ It is used in making casts for statues, models.
↪ It is used to make room interior, false wall and ceiling etc.
↪ It is used in movie to simulate appearance of wood, stone, metal etc.
↪ It is used in plastering the fractured bones.
↪ It is used for making black board chalk.
↪ It is used to make fire proof bricks.
↪ It is used for making artificial marbles.