Question

Match the following items in column I with the corresponding items in column II.

| Column I| | Column II
---|---|---|---
(i)| $N{{a}_{2}}C{{O}_{3}}.5{{H}_{2}}O$| (A)| Portland cement ingredient
(ii)| $Mg{{(HC{{O}_{3}})}_{2}}$| (B)| Castner Kellner Process
(iii)| NaOH| (C)| Solvay process
(iv)| $C{{a}_{3}}A{{l}_{2}}{{O}_{6}}$| (D)| Temporary hardness

(a) $(i)\to (C);(ii)\to (B);(iii)\to (D);(iv)\to (A)$
(b) $(i)\to (C);(ii)\to (D);(iii)\to (B);(iv)\to (A)$
(c) $(i)\to (D);(ii)\to (A);(iii)\to (B);(iv)\to (C)$
(d) $(i)\to (B);(ii)\to (C);(iii)\to (A);(iv)\to (D)$

Answer 1

Hint : The basic ingredients of Portland cement are calcium and aluminium. The Castner Keller process is a process to synthesize an alkali. Solvay process is used for the synthesis of carbonate compounds. Temporary hardness is due to certain compounds dissolved in water.

Complete step by step solution :
- $N{{a}_{2}}C{{O}_{3}}.5{{H}_{2}}O$ can be synthesised commercially by a process called Solvay process, also known as ammonia-soda process. The ingredients for this are easily available and are inexpensive. Salt brine and limestone is used and the reaction involved is
$2NaCl+CaC{{O}_{3}}\to N{{a}_{2}}C{{O}_{3}}+CaC{{l}_{2}}$
- Temporary hardness is hardness of water due to the presence of bicarbonate salts of certain compounds. Temporary hardness is caused due to $Mg{{(HC{{O}_{3}})}_{2}}$ and carbonate of calcium. It is formed when water percolates through deposits of limestone, chalk or gypsum, which are largely made up of calcium, magnesium carbonates, bicarbonates and sulphates.
-Castner-Kellner is a process or a method of electrolysis on an aqueous alkali chloride solution to produce its corresponding alkali hydroxide. Usually NaOH is produced using this method. NaCl solution is subjected to electrolysis to give NaOH.
The reaction at the anode is
$C{{l}^{-}}\to \frac{1}{2}C{{l}_{2}}+{{e}^{-}}$
Reaction at cathode is
$N{{a}^{+}}+{{e}^{-}}\to Na$
- The main ingredients in Portland cement are calcium, silica, alumina and iron. Calcium exist as $C{{a}_{3}}A{{l}_{2}}{{O}_{6}}$ in Portland cement. Portland cement is a basic ingredient of concrete, mortar etc. It is a fine powder, formed by heating limestone and clay minerals in a kiln.

Thus, the correct option to this question is (A).

Note : Carbonates of calcium also cause temporary hardness. Some other alkalis are also synthesised by the Castner-Kellner process, but it is used for production of NaOH.