Question

The mixed anhydride of nitrogen is:

• A. ${\mathrm{N}}_2{\mathrm{O}}_2\left(\mathrm{NO}\right)$
• B. ${\mathrm{N}}_2{\mathrm{O}}_4\left(2{\mathrm{NO}}_2\right)$
• C. ${\mathrm{N}}_2{\mathrm{O}}_5$
• D. ${\mathrm{N}}_2{\mathrm{O}}_2$

Answer 1

The correct option is B

${\mathrm{N}}_2{\mathrm{O}}_4\left(2{\mathrm{NO}}_2\right)$

Explanation for correct option:

B. ${\mathrm{N}}_2{\mathrm{O}}_4\left(2{\mathrm{NO}}_2\right)$

Nitrogen can exist in oxidation states ranging from $+1\mathrm{to}+5$.

Reaction for the formation of Nitrous oxide:

• Nitrous oxide is formed when ammonium nitrate is heated.
• The chemical reaction can be depicted as:
• ${\mathrm{NH}}_4{\mathrm{NO}}_3\left(\mathrm{s}\right)\stackrel{∆}{\to }{\mathrm{N}}_2\mathrm{O}\left(\mathrm{g}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)$

Reaction for the formation of Nitrogen monoxide:

• Nitrogen monoxide is formed while sodium nitrate is reacted with ferrous sulfate in an acidic medium.
• The chemical reaction can be depicted as:

$2{\mathrm{NaNO}}_2\left(\mathrm{aq}\right)+2{\mathrm{FeSO}}_4\left(\mathrm{aq}\right)+3{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{Fe}}_2{\left({\mathrm{SO}}_4\right)}_3\left(\mathrm{aq}\right)+2{\mathrm{NaHSO}}_4\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)+2\mathrm{NO}\left(\mathrm{g}\right)$

Reaction for the formation of Nitrogen trixoide:

• When a mixture of equal parts of nitric oxide and nitrogen dioxide is cooled then dinitrogen trioxide will form.
• The chemical reaction can be depicted as:
• $2\mathrm{NO}\left(\mathrm{g}\right)+{\mathrm{N}}_2{\mathrm{O}}_4\left(\mathrm{g}\right)\stackrel{250\mathrm{K}}{\to }2{\mathrm{N}}_2{\mathrm{O}}_3\left(\mathrm{g}\right)$

Reaction for the formation of Nitrogen dioxide:

• Nitrogen dioxide is prepared commercially by heating the mixture of lead nitrate.
• The chemical reaction can be depicted as:
• $2\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+\mathrm{heat}\to 2\mathrm{PbO}\left(\mathrm{s}\right)+4{\mathrm{NO}}_2\left(\mathrm{g}\right)+{\mathrm{O}}_2\left(\mathrm{g}\right)$

Nitrogen dioxide is a mixture of anhydride i.e. the compound forms a mixture of two acidic anhydrides. Two oxides of nitrogen dioxide react with water to form nitrogen-containing mixed acids.

$2{\mathrm{NO}}_2\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{HNO}}_3\left(\mathrm{aq}\right)+{\mathrm{HNO}}_2\left(\mathrm{aq}\right)$

Hence, the mixed anhydride is ${\mathrm{N}}_2{\mathrm{O}}_4\left(2{\mathrm{NO}}_2\right)$.

Explanation for incorrect options:

The mixed anhydride is ${\mathrm{N}}_2{\mathrm{O}}_4\left(2{\mathrm{NO}}_2\right)$ which is confirmed by the reactions discussed above. Thus, options A, C, and D are incorrect.

Hence, the correct option is B i.e.${\mathrm{N}}_2{\mathrm{O}}_4\left(2{\mathrm{NO}}_2\right)$