Question

Why is the oxide in the higher oxidation state of the element more acidic than the one in lower oxidation state?

Answer 1

Compounds in which the central atom is present in a high oxidation state like $M{n}_2{O}_7$.

Mn is present in the +7 oxidation state, the compound is electron-deficient and has a tendency to accept electrons. Thus, it is acidic in nature.

Oxides in which the central metal atom is present in lower oxidation state can readily lose

electrons to achieve a higher oxidation state, thereby acting as a base.