Nitrous oxide is obtained by the thermal decomposition of

Options

A. ammonium carbonate
B. sodium azide
C. microcosmic salt
D. molten ammnium nitrate

Answer

D

Explanation

Nitrous oxide can be prepared by heating ammonium nitrate `(NH_(4)NO_(3)rarrN_(2)O+2H_(2)O)` or a mixture of sodium nitrate and ammonuium sulphate:
`2NaNO_(3)+(NH_(4))_(2)SO_(4)rarrunderset((2N_(2)O+4H_(2)O))underset(downarrowDelta)((2NH_(4)NO_(3))+Na_(2)SO_(4))`
The mixture consist of `3` parts ammonium sulphate and `4` parts sodium nitrate .It is heated carefully below `240^(@)C`. The evolved gas is collected over hot water as it is fairly soluble in cold water .It is usually contaminated with nitric oxide.(NO), ammonia (`NH_(3))`and water vapour. The gas is passed through ferrous sulphate solution to remove nitric oxide and through conc.`H_(2)SO_(4)` to remove ammonia and water vapour:
`FeSO_(4)+NO rarr FeSO_(4).NO`
`H_(2)SO_(4)+2NH_(3)rarr(NH_(4))_(2)SO_(4)`.