Oxidation number of sulphur in Caro's - Peroxymonosulfuric acid (H2SO5 )
2 + x - 10
x= +8
x= oxidation number of Sulphur
But this cannot be true as maximum oxidation number for S cannot exceed + 6. Since S has only 6 electrons in its valence shell.
This exceptional value of oxidattion state for sulphur in H2SO5 is due to the peroxy linkage shown by two atoms.
so, Oxidation number of S in H2SO5
2 (+1) + x + 3 (-2) + 2 (-1) [for peroxy linkage] = 0
2 + x -6 -2 = 0
x = + 6
so, Oxidation number of S in H2SO5 is +6.