Question

Which of the following reactions gives oxide of nitrogen which is in solid state and acidic in nature? \[ \begin{aligned} \text{I. }&\mathrm{NH_4NO_3}\xrightarrow{\Delta} \\ \text{II. }& 2\mathrm{Pb(NO_3)_2}\xrightarrow{\Delta} \\ \text{III. }&\mathrm{P_4O_{10}+4HNO_3}\rightarrow \\ \text{IV. }& 2\mathrm{NO}+\mathrm{N_2O_4}\xrightarrow[250\,K]{} \end{aligned} \] The correct answer is

• A. III, IV only
• B. I, III, IV only
• C. I, II, III only
• D. II, IV only

Hint:

Among nitrogen oxides: \[ \boxed{\mathrm{N_2O_5}} \] and \[ \boxed{\mathrm{N_2O_3}} \] are solid acidic oxides (under suitable low-temperature conditions for \(\mathrm{N_2O_3}\)).

Answer 1

The Correct Option is A

Step 1: Identify the nitrogen oxide formed in each reaction. \[ \mathrm{NH_4NO_3} \xrightarrow{\Delta} \mathrm{N_2O}+2\mathrm{H_2O} \] \(\mathrm{N_2O}\) is neutral and gaseous. \[ 2\mathrm{Pb(NO_3)_2} \xrightarrow{\Delta} 2\mathrm{PbO}+4\mathrm{NO_2}+\mathrm{O_2} \] \(\mathrm{NO_2}\) is acidic but gaseous. \[ \mathrm{P_4O_{10}+4HNO_3} \rightarrow 4\mathrm{HPO_3}+2\mathrm{N_2O_5} \] \(\mathrm{N_2O_5}\) is a solid acidic oxide. \[ 2\mathrm{NO}+\mathrm{N_2O_4} \xrightarrow{250\,K} 2\mathrm{N_2O_3} \] \(\mathrm{N_2O_3}\) is a solid acidic oxide at low temperature. Therefore, only reactions \[ \boxed{\mathrm{III}\ \text{and}\ \mathrm{IV}} \] produce nitrogen oxides that are solid and acidic. Hence, \[ \boxed{(A)} \] is the correct answer.