Question

“A” obtained by Ostwald’s method involving air oxidation of\( NH_3\), upon further air oxidation produces “B”. “B” on hydration forms an oxoacid of Nitrogen along with evolution of “A”. The oxoacid also produces “A” and gives positive brown ring test. 

• A. \(NO, NO_2\)
• B. \(N_2O_3, NO_2\)
• C. \(NO_2, N_2O_4\)
• D. \(NO_2, N_2O_5\)

Hint:

For questions involving industrial processes:
• Understand key steps in the process (e.g., oxidation, hydration, and product formation).
• Focus on intermediate and final products to identify properties and tests.

Answer 1

The Correct Option is A

1.Ostwald Process: In the Ostwald process, ammonia (\(\text{NH}_3\)) is oxidized by air to form nitric oxide (\(\text{NO}\)):
\[4\text{NH}_3 + 5\text{O}_2 \xrightarrow{\text{Pt, 500$^\circ$C}} 4\text{NO} + 6\text{H}_2\text{O}.\]
Thus, “A” is NO.
2. Further Oxidation of NO: Nitric oxide (\(\text{NO}\)) reacts with oxygen to form nitrogen dioxide (\(\text{NO}_2\)):
\[2\text{NO} + \text{O}_2 \rightarrow 2\text{NO}_2.\]
Thus, “B” is NO\(_2\).
3. Hydration of NO\(_2\): Nitrogen dioxide (\(\text{NO}_2\)) reacts with water to form nitric acid (\(\text{HNO}_3\)) and nitric oxide (\(\text{NO}\)):
\[3\text{NO}_2 + \text{H}_2\text{O} \rightarrow 2\text{HNO}_3 + \text{NO}.\]
4. Properties of HNO\(_3\): Nitric acid is an oxoacid of nitrogen. It gives a positive brown ring test, confirming the presence of NO.
Final Answer: \((3)\) \(\text{NO, NO}_2\).