Purple solution of $KMnO_4 \xrightarrow{Na_2SO_4, BaCl_2}$ Pink ppt. Select the correct statement about pink ppt.

When $CuSO_4$ reacts with $KI$,the oxidation number of $Cu$ changes by

$AgCl$ on fusion with $Na_2CO_3$ forms

$KMnO_4$ acts as an oxidising agent in acidic medium. $X$ is the difference between the oxidation states of $Mn$ in reactant and product. $Y$ is the number of $d$ electrons present in the brown red precipitate formed at the end of the acetate ion test with neutral ferric chloride. The value of $X+Y$ is $.........$

$2 \text{ mol}$ of $FeSO_4$ are oxidized by $X \text{ mol}$ of $KMnO_4$ whereas $2 \text{ mol}$ of $FeC_2O_4$ are oxidized by $Y \text{ mol}$ of $KMnO_4$. The ratio of $X$ and $Y$ is:

Number of moles of $MnO_4^{-}$ required to oxidise one mole of ferrous oxalate completely in acidic medium will be $:-$ (in $mole$)