In lanthanides, there is poorer shielding of $5 d$ electrons by $4f$ electrons resulting in greater attraction of the nucleus over $5d$ electrons and reduction of the atomic radii.
$2MnO_4^ - + 5{C_2}O_4^{2 - } + 16{H^ + } \to 2M{n^{2 + }} + 10C{O_2} + 8{H_2}O$
અહીં $20\,ml$ $0.1\,M$ $KMn{O_4}$ કોના બરાબર છે?