Question

Assertion: Chlorine undergoes dispropor-tionation reaction in alkaline medium.
Reason: $C{l}_2$ 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)

$C{l}_2+2NaOH(dil.)\stackrel{\text{cold}}{\to }NaCl+NaOCl+H_{2}O$

$3C{I}_2+6NaOH(conc.)\stackrel{\text{heat}}{\to }5NaCl+NaCl{O}_3+3H_{2}O$

Chlorine undergoes the simultaneous oxidationreduction. Chlorine is simultaneously reduced to chloride ion $\left(C{l}^{-}\right)$ and is oxidised to either $Cl{O}^{-}$ or $Cl{O}_3-$ ion. Halogens $(e.g.Cl)$ have a strong tendency to accept electrons, so they act as strong oxidising agents.