Which one of the following oxides is amphoteric?

Options

A. `Mn_(2)O_(7)`
B. `CrO`
C. `V_(2)O_(4)`
D. `Cr_(2)O_(3)`

Answer

D

Explanation

The oxide, in which metal is present in its intermediate oxidation state, is amphoteric in nature. The oxidation states of metal in the given oxides are as
`overset(+7)(Mn)_(2)O_(7),overset(+2)(Cr_(2))O,overset(+4)(V_(2))O_(4),overset(+3)(Cr_(2))O_(3),overset(+3)(V_(2))O_(3)`
Thus, `Cr_(2)O_(3)` is an amphoteric oxide, i.e, it reacts with acids as well as base.