Question

Why does increase in oxidation state increase electronegativity?

Answer 1

Electronegativity is simply a measure of an ability of an atom to attract electrons in a covalent framework. So keeping in mind that like charges repel (electrons repel electrons) it follows that elements in a high oxidation state are more electronegative - i.e. more able to attract and stabilize electrons.

Hope it helps you.....

Answer 2

greater electronegativity means that the affinity(attraction) of electron towards the atom is more.
and we know electron is negatively charged so more is the positive charge on atom greater is electron attracted towards it
so atom with higher oxidation state tends to attract electron greatly