Which of the following act both as an oxidising as well as reducing agent ?

Options

A. `H_(3)PO_(4)`
B. `HNO_(3)`
C. `HNO_(2)`
D. `SO_(3)`

Answer

C

Explanation

O.N. of P in `H_(3)PO_(4)=+5` (Highest)
O.N. of N is `HNO_(3)=+5` (Highest)
O.N of N in `HNO_(2)=+3`
O.N of N in `HNO_(2)=+3`
O.N of N is `SO_(3)=+6` (Highest)
As O.N of nitrogen in `HNO_(2)` is +3, it means increase or decrease its O.N. Thus `HNO_(2)` acts both as an oxidisingom as well as reducing agent.