question_answer

  In one of the industrial processes used for manufacture of sodium hydroxide, a gas X is formed as by-product. The gas X reacts with lime water to give a compound Y which is used as a bleaching agent in chemical industry. Identify X and Y giving the chemical equation of the reactions involved    [NCERT Exemplar]

Answer:

               In the manufacture of sodium hydroxide, hydrogen gas and chlorine gas (X) are formed as by-products. When chlorine gas (X) reacts with lime water, it forms calcium oxychloride (bleaching powder) Y. The reactions are 2NaCl(aq) + 2H2O(l) ® 2NaOH(aq) + Cl2(g) + H2(g) X ? Cl2 (Chlorine gas) Ca(OH)2(s) + Cl2(g) ® CaOCl2(s) +H2O(l) Y ? Calcium oxychloride (bleaching powder)