Question

36. When Cl, gas reacts with hot and concentrated
sodium hydroxide solution, the oxidation number of
chlorine changes from [AIPMT (Prelims)-2012]
(1) Zero to -1 and zero to +3
(2) Zero to +1 and zero to -3
(3) Zero to +1 and zero to -5
(4) Zero to -1 and zero to +5​

Answer 1

When Cl2 gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from 0 to -1 and 0 to +5. ​

Oxidation number of Cl is 0 in Cl2, -1 in NaCl and +5 in NaClO3