Question

Match the important chemicals given in Column (A) with the chemical formulae given in Column(B)

Column 1	Column 2
Plaster of Paris	Ca(OH)2
Gypsum	${\mathrm{CaSO}}_4.\frac{1}{2}{\mathrm{H}}_2\mathrm{O}$
Bleaching Powder	CaSO4.2H2O
Slaked Lime	CaOCI2

Answer 1

(A) Plaster of Paris - (ii) ${\mathbf{CaSO}}_{\mathbf{4}}\mathbf{.}\frac{\mathbf{1}}{\mathbf{2}}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}$

1. Plaster of Paris is a popular chemical substance that is utilized most commonly for sculpting materials and in gauze bandages.
2. Usually white in color and available in powder form.

(B) Gypsum - (iii) ${\mathbf{CaSO}}_{\mathbf{4}}\mathbf{.}\mathbf{2}{\mathbf{H}}_{\mathbf{2}}\mathbf{O}$

1. Gypsum is a soft sulfate mineral composed of calcium sulfate dehydrate.
2. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard/sidewalk chalk, and drywall.

(C) Bleaching powder - (IV) ${\mathbf{CaOCI}}_{\mathbf{2}}$

1. It is a white powder that gives a strong smell of chlorine.
2. It is soluble in cold water.
3. It reacts with dilute acids to produce chlorine. When bleaching powder is treated with an excess of a dilute, all the chlorine present in it is liberated.

(D) Slaked lime - (I) $\mathbf{Ca}{\mathbf{\left(}\mathbf{OH}\mathbf{\right)}}_{\mathbf{2}}$

1. Slaked lime is the common name for calcium hydroxide.
2. In sewage treatment, one major application of slaked lime is as a flocculant.

Final Answer: The correct matching is represented in the following table:

Column (A)	Column (B)
(A) Plaster of Paris	(II) ${\mathrm{CaSO}}_4.\frac{1}{2}{\mathrm{H}}_2\mathrm{O}$
(B) Gypsum	(III) ${\mathrm{CaSO}}_4.2{\mathrm{H}}_2\mathrm{O}$
(C) Bleaching powder	(IV) ${\mathrm{CaOCI}}_2$
(D) Slaked lime	(I) $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$