Question

80. When \( Cl _{2} \) gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from (1) zero to \( +1 \) and zero to \( -5 \) (2) zero to \( -1 \) and zero to \( +5 \) (3) zero to \( -1 \) and zero to \( +3 \) (4) zero to \( +1 \) and zero to \( -3 \)

Answer 1

The reaction of chlorine gas with hot and concentrated sodium hydroxide solution is 

3Cl₂ ​+ 6NaOH⟶NaClO₃ ​+ 5NaCl+3H₂O 

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

So the oxidation number of chlorine changes from Zero to -1 and Zero to +5.