$n-$ factors of $FeC_2O_4=3,\,Fe_2(SO_4)_3$ does not react
$n-$ factors of $Fe_2(C_2O_4)_3=6$,
$n_{eq}\,KMnO_4=n_{eq}[FeC_2O_4+Fe_2(C_2O_4)_3+FeSO_4]$
or, $x \times 5=1 \times 3+1\times 6+1\times1 $
$x=2$
$PC{l_5}\xrightarrow{\Delta }PC{l_3} + C{l_2}$
$14{H^ + } + C{r_2}O_7^{2 - } + 3Ni \to 2C{r^{3 + }} + 7{H_2}O + 3N{i^{2 + }}$
$5{H_2}{O_2} + \,xCl{O_2}\, + 2O{H^ - }\, \to \,xC{l^ - }\, + \,y{O_2} + 6{H_2}O$