Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
The number of moles $\mathrm{KMnO}_4$ that will be needed to react with one mole of sulphite ion in acidic solution is:
ChemistryRedox ReactionsJEE Main
Options:
  • A $4 / 5$
  • B $2 / 5$
  • C 1
  • D $3 / 5$
Solution:
2294 Upvotes Verified Answer
The correct answer is: $2 / 5$
The balanced chemical equation is:
$2 \mathrm{MnO}_4^{-}+ 6 \mathrm{H}^{+}+5 \mathrm{SO}_3^{--} \longrightarrow 2 \mathrm{Mn}^{++}+5 \mathrm{SO}_4^{--}+3 \mathrm{H}_2 \mathrm{O}$
From the equation it is clear that
Moles of $\mathrm{MnO}_4^{-}$ require to oxidise 5 moles of $\mathrm{SO}_3^{--}$are 2
Moles of $\mathrm{MnO}_4^{-}$ require to oxidise 1 mole of $\mathrm{SO}_3^{--}$are $2 / 5$.

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.