Question

The industrial process used for the manufacture of caustic soda involves electrolysis of an aqueous solution of compound ‘X’. In this process, two gases ‘Y’ and ‘Z’ are liberated. ‘Y’ is liberated at cathode and ‘Z’, which is liberated at anode, on treatment with dry slaked lime forms a compound ‘B’. Name X, Y, Z and B.

Answer 1

X = NaCl (Sodium chloride);

Y = H₂ (Hydrogen gas);

Z = Cl₂ (Chlorine gas);

B = Bleaching powder (CaOCl₂)

\[\ce{2NaCl_{(aq)} + 2H2O_{(l)} -> 2NaOH_{(aq)} + Cl2_{(g)} + H2_{(g)}}\]

\[\ce{Ca(OH)2 + Cl2 -> CaOCl2 + H2O}\]