NEET2012Chemistryp Block Elements (Group 15, 16, 17 & 18)Actual
When Cl ₂ gas reacts with hot and concentrated sodium hydroxide solution, the oxidation number of chlorine changes from
Options
- Azero to +1 and zero to -5
- Bzero to -1 and zero to +5
- Czero to -1 and zero to +3
- Dzero to +1 and zero to -3
Correct answer
B. zero to -1 and zero to +5
Step-by-step solution
When chlorine gas reacts with hot and concentrated NaOH solution, it disproportionates into chloride ( Cl ⁻ ) and chlorate ( ClO ₃⁻ ) ions. In this process, oxidation number of chlorine changes from 0 to -1 and 0 to +5 . Note In disproportionation reactions, the same element undergoes oxidation as well as reduction.