iii) Quick lime: It is used: a. in the preparation of cement, glass and calcium carbide. b. In the purification of sugar c. In softening of hard water d. As a flux in the extraction of metal
iv) Lime stone: It is used a) as building material b) in the manufacture of quick lime c) in Solvay process to prepare Na2CO3 as it is a source of CO2 d) in metallurgy for the extraction of iron e) in toothpaste and certain cosmetics
v) Cement: It is an important building material. It is used in concrete and reinforced concrete, in plastering and in the construction of bridges, dams and buildings.
vi) Plaster of paris: It is used a) in making moulds for pottery and ceramics etc. b) in surgical bandages for setting broken bones of the body
c) for making statues, models, decorative materials and black board chalk.
Biological importance of Ca and Mg
i) Magnesium ions are concentrated in animal cells and Calcium ions are concentrated in body fluids, outside the cell.
ii) All enzymes that utilize ATP in phosphate transfer require magnesium ion as cofactor.
iii) In green plants magnesium is present in chlorophyll.