JEE MainChemistryp Block Elements (Group 15, 16, 17 & 18)
The nature of the products formed during the oxidation of metals by nitric acid depends on the concentration of the acid used. When copper metal is treated with dilute nitric acid and concentrated nitric acid respectively, the major nitrogen-containing gases evolved are:
Options
- AN ₂ O and NO ₂
- BNO ₂ and NO
- CNO and NO ₂
- DNO and N ₂ O
Correct answer
C. NO and NO ₂
Step-by-step solution
The reaction of copper with nitric acid yields different reduction products of nitrogen depending on the acid's concentration. With dilute nitric acid, nitric oxide ( NO ) is evolved: 3 Cu + 8 HNO ₃ (dilute) 3 Cu ( NO ₃)₂ + 2 NO + 4 H ₂ O With concentrated nitric acid, nitrogen dioxide ( NO ₂ ) is evolved: Cu + 4 HNO ₃ (conc.) Cu ( NO ₃)₂ + 2 NO ₂ + 2 H ₂ O Answer: NO and NO ₂