The weight of KMnO₄ that can oxidise 100ml of. 0.2M oxalic acid in acidic medium is [Mol. wt of KMnO₄ = 158]

                KMnO₄                                                                                              

n-factor in acidic medium = 5  

$\left({\mathrm{MnO}}_4^{-}\to {\mathrm{Mn}}^{+2}\right)$  

Oxalic acid

n-factor = 2

$\left({\mathrm{C}}_2{\mathrm{O}}_4^{-2}\to 2{\mathrm{CO}}_2\right)$

$\mathrm{GEW}=\frac{158}{5}\mathrm{g}$

V= 100ml

 N = 0.2(2) = 0.4N

At neutralization point ,

 V₁N₁= V₂N₂

$\frac{\mathrm{W}}{\mathrm{GEW}}=\frac{\mathrm{VN}}{1000}$

     $\frac{\mathrm{W}}{\frac{158}{5}}=\frac{100(0.4)}{1000}$                                        

 W=1.264g