Correct Answer - 4
It is an acidic oxide. It reacts with water with hissing sound forming nitric acid:
`N_(2)O_(5)+H_(2)Orarr2HNO_(3)`
On account of this, it is know as nitric anhydride. With alkalis it forms nitrates:
`N_(2)O_(5)+2NaOH rarr 2NaNO_(3)+H_(2)O`
