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 .