10.21 Describe the importance of the following : (i) limestone (ii) cement (iii) plaster of paris.
(i) Limestone-
The chemical formula is .
Importance of limestone is-
(ii) Cement-
Cement is an important building material. It is a mixture of tricalcium silicate() and tricalcium aluminate().
Importance of cement-
It is used in concrete and reinforced concrete, in plastering and in the construction of bridges, dams and buildings
(iii) Plaster of Paris-
It is a hemihydrate of calcium sulphate. It is obtained when gypsum, , is heated to 393 K.
Importance of POP-
It is used in medicine as surgical bandages and also it is used for making casts and moulds.