At 298 K, the standard reduction potentials are 1.51 V for MnO_4^- ∣ Mn^2+, 1.36 V for Cl_2 ∣ Cl^-, 1.07 V for Br_2 ∣ Br^-, and 0.54 V for I_2 ∣ I^-.…

At $\displaystyle 298$ K , the standard reduction potentials are $\displaystyle 1.51$ V for $\displaystyle \mathrm{MnO}_4^{-} \mid \mathrm{Mn}^{2+}$, $\displaystyle 1.36$ V for $\displaystyle \mathrm{Cl}_2 \mid \mathrm{Cl}^{-}, 1.07 \mathrm{~V}$ for $\displaystyle \mathrm{Br}_2 \mid \mathrm{Br}^{-}$, and $\displaystyle 0.54$ V for $\displaystyle \mathrm{I}_2 \mid \mathrm{I}^{-}$. At $\displaystyle \mathrm{pH}=3$, permanganate is expected to oxidize : $\displaystyle \left(\frac{\mathrm{RT}}{\mathrm{F}}=0.059 \mathrm{~V}\right)$