Quick lime or Calcium oxide (CaO)
It is prepared on a commercial scale by heating limestone(CaCO3) in a rotary kiln at 1070-1270 K.
CaO + CO2
The carbon dioxide is removed as soon as it is produced to enable the reaction to proceed to completion.
It is an important primary material for manufacturing cement and is the cheapest form of alkali.
It is used in the manufacture of sodium carbonate from caustic soda.
Plaster of Paris or Calcium Sulphate( CaSO4. 1/2H2O)
It is a hemihydrate of calcium sulphate and is obtained when gypsum is heated to 393K.
2(CaSO4.2H2O) → 2(CaSO4).H2O + 2H2O
•Used in hospitals as plaster for supporting fractured bones in the right position.
•Used for making decorative materials and for making surfaces smooth.
•Used as a fire-proofing material