What is the oxidation number of sulfur in $H_2SO_5$?

What is the difference in oxidation number of $Mn$ in $KMnO_4$ and $MnO_2$?

Oxidation numbers of $P$ in $PO_4^{3-}$,of $S$ in $SO_4^{2-}$ and that of $Cr$ in $Cr_2O_7^{2-}$ are respectively

In the chromyl chloride test for the confirmation of $Cl^{-}$ ion,a yellow solution is obtained. Acidification of the solution and the addition of amyl alcohol and $10\% H_2O_2$ turns the organic layer blue,indicating the formation of chromium pentoxide. The oxidation state of chromium in that compound is:

The oxidation states of $P$ atom in $POCl_3$,$H_3PO_3$ and $H_4P_2O_6$,respectively are

The difference in oxidation state of chromium in chromate and dichromate salts is $....$ .