Question

Match the following columns.

Column (I)	Column(II)
(1) Plaster of Paris	(i) Ca(OH)${}_2$
(2) Gypsum	(ii) CaSO${}_4$.$\frac{1}{2}$H${}_2$O
(3) Bleaching powder	(iii) CaSO${}_4$.2H${}_2$O
(4) Slaked lime	(iv) CaOCl${}_2$

• 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

Answer: (A)

(1) $\to$ (ii), (2) $\to$ (iii), (3) $\to$ (iv), (4) $\to$ (i)

1) Plaster of Paris is ${CaSO}_4\cdot \frac{1}{2}{H}_{2}O$. It is calcium sulphate and it differs from gypsum only with water of crystallization.
2) Gypsum is formed if plaster of paris absorbs moisture becomes a hard material.
${CaSO}_4\cdot 2H_{2}O$
3) Bleaching powder is calcium oxychloride which is used for bleaching purposes.
4) Slaked lime is known as calcium hydroxide.