Question

Match the following columns.

Column I	Column II
1. Plaster of Paris	i. $Ca{(OH)_2}$
2. Gypsum	ii. $CaS{O_4}.\dfrac{1}{2}{H_2}O$
3. Bleaching Powder	iii. $CaS{O_4}.2{H_2}O$
4. Slaked Lime	iv. $CaOC{I_2}$

A. (1)$\to$ (ii), (2)$\to$(iii), (3)$\to$(iv), (4) $\to$(i)
B. (1)$\to$(iii), (2)$\to$(ii), (3)$\to$(iv), (4) $\to$(i)
C. (1)$\to$(i), (2)$\to$(iii), (3)$\to$(iv), (4)$\to$(ii)
D. (1)$\to$(iii), (2)$\to$(iii), (3)$\to$(iv), (4)$\to$(i)

Answer 1

In this question we have found a chemical formula of given examples and match the correct answer. A chemical formula is a way of presenting information about chemical proportions of atoms that constitute a particular chemical compound using chemical elements, symbols, and numbers.

Complete step by step solution:
1. Plaster of Paris: The chemical formula for the plaster of Paris is $(CaS{O_4}).\dfrac{1}{2}{H_2}O$ and is better known as calcium sulfate hemihydrate. It consists of fine white powder, which hardens when moistened and allowed to dry.
2. Gypsum: Gypsum is composed of calcium sulphate $(CaS{O_4})$ and water $({H_2}O)$. Its chemical name is calcium sulphate dihydrate. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard and drywall.
3. Bleaching powder: Bleaching powder formula or calcium hydrochloride formula is explained here along with its structure. It should be noted that calcium hypochlorite is the main ingredient of bleaching powder, which is an inorganic compound and thus, both are often used simultaneously. Its chemical formula is $Ca(OC{l_2})$
4. Slake lime: Calcium hydroxide called slaked lime is an inorganic compound and it is a colorless crystal and is obtained when calcium oxide is mixed with water, it is used in preparation of dry mixes for painting and white washing and its chemical formula is $Ca{(OH)_2}$. It has many names including hydrated lime caustic lime or pickling lime.

**Hence,
Plaster of Paris $\rightarrow CaS{O_4}.\dfrac{1}{2}{H_2}O$
Gypsum $\rightarrow CaS{O_4}.2{H_2}O$
Bleaching powder $\rightarrow CaOC{I_2}$
Slake lime $\rightarrow Ca{(OH)_2}$

Note:**
A chemical formula identifies each constituent element by its chemical symbol and indicates the proportionate number of atoms of each element. There is special nomenclature of chemical compounds for example, Gypsum is composed of calcium sulphate and water. Its chemical name is calcium sulphate dihydrate.