Question 21
Describe the importance of the following: (i) limestone (ii) cement (iii) plaster of paris.
(i) Chemically, limestone is CaCO3.
Importance of limestone
(a) It is used in the preparation of lime and cement.
(b) It is used as a flux during the smelting of iron ores.
(ii) Chemically, cement is a mixture of calcium silicate and calcium aluminate.
Importance of cement
(a) It is used in plastering and in construction of bridges.
(b) It is used in concrete.
(iii) Chemically, plaster of Paris is 2CaSO4.H2O.
Importance of plaster of Paris
(a) It is used in surgical bandages.
(b) It is also used for making casts and moulds.
