Match the compounds given in Column I with their uses mentioned in Column II.


(i) → (c)

Calcium carbonate used in manufacturing high quality paper because the paper and cardboard industries use lime-based coating pigments and filters such as GCC(Ground Calcium Carbonate). GCC is made from concentrated and fine-ground calcium carbonate and used to make fine paper, cardboard packaging and pulp-based paper.


(ii)(d)


Calcium Hydroxide is used in white washing because for white washing walls as it slowly reacts with CO2in air to form a thin layer of Calcium Carbonate on the walls. The layer of Calcium Carbonate gives a shiny finish to the walls.


Ca(OH)2 + CO2 CaCO3 + H2O


(iii)(b)


CaO is used in manufacturing of sodium carbonate from caustic soda.


Above process is also known as Solvay Process. This reaction occurs in two steps.


First step,


NaCl + CO2 + NH3 + H2O NaHCO3 + NH4Cl(l)


First Ammonia converts into Sodium Hydrogen Carbonate and Ammonium Chloride.


Second Step,


2NaCl + CaCO3 Na2CO3 + CaCl2


So, in the next or second step, there is the formation of Sodium Carbonate.


(iv)(a)


CaSO4 is used in Dentistry, Ornamental work because CaSO4with adequate quantity of water, it forms a plastic mass that sets into a hard solid.


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