Which of the following statements about oxides of nitrogen are correct?

A $N X_{2} O X_{5}$ is the anhydride of nitrous acid, $HNO X_{2}$ .
B $N X_{2} O$ is a neutral oxide.
C $NO$ is oxidised by the oxygen of air to $NO X_{2}$ at room temperature.
DOn cooling, brown $NO X_{2}$ dimerises to colourless, diamagnetic $N X_{2} O X_{4}$ .

Answer: B, C, D

The odd electrons of two

NO X_{2}

molecules pair up to form the N-N bond of

N X_{2} O X_{4}

, giving a colourless diamagnetic dimer.

2 NO + O X_{2} 2 NO X_{2}

occurs readily in air.

N X_{2} O X_{5}

is the anhydride of

HNO X_{3}

, not

HNO X_{2}

N X_{2} O

is neutral. Correct: A, B, D.