Question

Permanganate titration is not carried out in the presence of hydrochloric acid because

• A. In acidic medium $KMn{O}_4$ does not react
• B. $HCl$ get oxidised to $C{l}_2$
• C. $HCl$ form complex compound with $Mn{O}_4^{-}$
• D. None of the above

Answer 1

The correct option is B $HCl$ get oxidised to $C{l}_2$

Permanganate titration is not carried out in the presence of hydrochloric acid because some of the hydrochloric acid gets oxidised to chlorine gas. Hence, we do not get the correct endpoint for any given titration.

$2KMn{O}_4\left(aq\right)+16HCl\left(aq\right)\to 2KCl\left(aq\right)+2MnC{l}_2\left(aq\right)+8H_{2}O\left(l\right)+5C{l}_2\left(g\right)\uparrow$

Hence, option (b) is correct.