Properties of Compounds of Nitrogen

In the detection of the nitrate ion, a brown complex in the form of a brown ring is formed at the junction of the two liquids. How many unpaired electrons does this brown complex contain?

In brown ring test for nitrate ions, brown ring is formed having composition 

Concentrated nitric acid turns the colour of the skin into-

The brown ring test for nitrates depends upon

When ${\mathrm{PbO}}_2$ reacts with concentrated ${\mathrm{HNO}}_3$, the gas evolved is

Identify the reaction which does not liberate ${\mathrm{N}}_2$

Complete the following chemical reaction.

${\mathrm{S}}_8 + \mathrm{Conc}.{\mathrm{HNO}}_3 \stackrel{ }{\to }$
 

Complete the following chemical reaction.

${\mathrm{I}}_2 + \mathrm{conc}. {\mathrm{HNO}}_3 \stackrel{ }{\to }$

A metal $\mathrm{M}$ can give the following observable change in a sequence of reactions.

$\mathrm{M}\underset{{\mathrm{HNO}}_3}{\overset{\mathrm{diluted}}{\to }}\mathrm{colourless} solution\underset{\mathrm{NaOH}}{\overset{\mathrm{aq}}{\to }}\mathrm{white} \mathrm{ppt}.\underset{\mathrm{NaOH}}{\overset{\mathrm{excess}}{\to }}\mathrm{colourless} solution\stackrel{{\mathrm{H}}_2\mathrm{S}}{\to }\mathrm{white} \mathrm{ppt}.$

The metal $\mathrm{M}$ is :

Reaction of ${\mathrm{HNO}}_3$ with $\mathrm{I}, \mathrm{S}, \mathrm{P}$ and $\mathrm{C}$ gives respectively:

Both $\mathrm{Be}$ and $\mathrm{Al}$ become passive on reaction with conc. nitric acid due to :

Which of the following salt will not give positive brown ring test?

$\mathrm{KCl}+\mathrm{Conc}.{\mathrm{H}}_2{\mathrm{SO}}_4+{\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7\stackrel{\mathrm{\Delta }}{⟶}\mathrm{X}\stackrel{\mathrm{NaOH}}{⟶}\mathrm{Y}$

$\left(\mathrm{X}\right)$ is reddish brown coloured gas soluble in $\mathrm{NaOH}$ forming $\left(\mathrm{Y}\right). \left(\mathrm{X}\right)$ and $\left(\mathrm{Y}\right)$ are :-

When zinc reacts with very dilute ${\mathrm{HNO}}_3$, the oxidation state of nitrogen changes from :-

Which of the following reaction is incorrectly written ?

When copper is heated with conc.${\mathrm{HNO}}_3$ it produces ?

Which of the following is correct about ammonia?

When copper is heated with conc. ${\mathrm{HNO}}_3$ it produces
 

In the brown ring test, brown colour of the ring is due to

A brown ring is formed in the ring test for ${\mathrm{NO}}_3^{-}$ ion. It is due to the formation of