Chemistry - Redox Reactions Question with Solution | TestHub

With $\mathrm{NaOH}$, $\mathrm{KHS}{\mathrm{O}}_3$ acts as a monoacid ($\mathrm{HS}{\mathrm{O}}_3^{-}$ $\to$ $\mathrm{S}{\mathrm{O}}_3^{2-}$, $n$ = 1); with $\mathrm{HCl}$ it acts as a monobasic species ($\mathrm{HS}{\mathrm{O}}_3^{-}$ $\to$ ${\mathrm{H}}_2\mathrm{S}{\mathrm{O}}_3$, $n$ = 1). Equal moles react in both cases, so equal volumes of 0.5 M acid and 0.5 M base are consumed - I is correct. II is correct and is exactly why the n-factor is 1 on both sides, so II explains I. Hence (a).