Neet Solved Paper 2013 Question 27
Question: $ KMn{O_4} $ can be prepared from $ {K_2}Mn{O_4} $ as per reaction $ 3MnO_4^{2-}+2H _2O2MnO_4^{-} $ $ +MnO _2+4O{H^{-}} $ The reaction can go to completion by removing $ O{H^{-}} $ ions by adding
Options:
A) HCI
B) KOH
C) $ CO _2 $
D) $ SO _2 $
Show Answer
Answer:
Correct Answer: D
Solution:
Since, $ O{H^{-}} $ are generated from weak acid $ (H _2O), $ a weak acid (like $ CO _2 $ ) should be used to remove it because of strong acid (HCI) reverse the reaction.
KOH increases the concentration of $ O{H^{-}}, $ thus again shifts the reaction in backward side. $ CO _2 $ combines with OH" to give carbonate which is easily removed.
$ SO _2 $ reacts with water to give strong acid, so it cannot be used.
