A white crystalline solid 'A' on boiling with caustic soda solution gives a gas 'B', which on passing through an alkaline solution of ptassium tetraiodomercurate (II) solution gives a brown ppt. the substance 'A' on heating eveolves a neutral gas 'C', which is inert at room temperature and reactive a presence of catalyst and does ont give grown fumes with nitric oxide.
Q. The substance 'A' is:

Options

A. `NH_(4)Cl`
B. `NH_(4)NO_(3)`
C. `NH_(4)NO_(2)`
D. `NaNO_(3)`

Answer

C

Explanation

`underset((A))(NH_(4)NO_(2))+NaOH to underset((B))(NH_(3)uarr)+NaNO_(2)+H_(2)O`
`NH_(3)+2K_(2)[HgI_(4)]+3KOH to underset("Brown ppt.")([HgO*Hg(NH_(2))_(2)])I darr+3H_(2)O +7KI`
`NH_(4)NO_(2) to underset((C))(N_(2)(g))+2H_(2)O`