Question

A chemical compound ‘X’ is used in the soap and glass industry. It is prepared from brine.
(a) Write the chemical name, common name and chemical formula of ‘X’.
(b) Write the equation involved in its preparation.
(c) What happens when it is treated with water containing $Ca$ and $Mg$ salts?

Answer 1

Hint: A compound that is prepared from brine should have the sodium atom as one of its constituents. Sodium carbonate is a chemical compound with the molecular formula\[N{a_2}C{O_3}\]. It's commonly referred to as washing soda and is used in cleaning products, glass production, as a food additive, and more.

Complete step by step answer:
The chemical compound ‘X’ here is the sodium carbonate that is used in the soap industry and in the glass industry. Hard water contains dissolved compounds, usually calcium or magnesium compounds. Sodium carbonate is used for removing temporary and permanent hardness of water. Sodium carbonate serves as a flux for silica, lowering the melting point of the mixture to something achievable without special materials.
(a) The chemical name is Sodium carbonate. Its common name is Washing Soda. The chemical formula of the compound in its hydrated form is \[N{a_2}C{O_3}.10{H_2}O\] and the chemical formula in its hydrated form is \[N{a_2}C{O_3}\].
(b) Sodium carbonate is prepared in the industries by various processes. One such common process is the thermal decomposition of sodium bicarbonate. The reaction that is involved here is as follows:
$NaCl + N{H_3} + C{O_2} + {H_2}O \to NaHC{O_3} + N{H_4}Cl$
$2NaHC{O_3} \to N{a_2}C{O_3} + {H_2}O + C{O_2}$
Thus, in the manufacture process, we can find the use of brine ($NaCl$ ) in the production of sodium carbonate.
(c) As sodium carbonate is water-soluble and magnesium carbonate and calcium carbonate are insoluble, so it is used to soften water by removing \[M{g^{2 + }}\] and \[C{a^{2 + }}\]. Thus, when sodium carbonate is treated with water containing $Ca$ and $Mg$ salts, it removes them and thus, softens the water.

Note:
 Some common applications of sodium carbonate (or washing soda) include:
(i) Sodium carbonate (or washing soda) is used as a cleansing agent for domestic purposes like washing clothes. Sodium carbonate is a component of many dry soap powders.
(ii) It is used for removing the temporary and permanent hardness of water.
(iii) It is used in the manufacture of glass, soap and paper.