Question

Assertion: Chlorine undergoes dispropor-tionation reaction in alkaline medium.
Reason: $Cl_2$ is an oxidising agent.

• A. If both assertion and reason are true and reason is the correct explanation of assertion
• B. If both assertion and reason are true but reason is not the correct explanation of assertion
• C. If assertion is true but reason is false
• D. If both assertion and reason are false

Answer 1

Answer: (B)

$Cl_2 + 2NaOH (dil.) \xrightarrow{\text{cold}} NaCl + NaOCl + H_2O$

$3CI_2 + 6NaOH (conc.) \xrightarrow{\text{heat}} 5NaCl + NaClO_3 + 3H_2O$

Chlorine undergoes the simultaneous oxidationreduction. Chlorine is simultaneously reduced to chloride ion $\left( Cl ^{-}\right)$ and is oxidised to either $Cl O ^{-}$ or $ClO _{3}-$ ion. Halogens $(e . g . Cl )$ have a strong tendency to accept electrons, so they act as strong oxidising agents.