JEE MainChemistryp Block Elements (Group 15, 16, 17 & 18)
When white phosphorus reacts with concentrated HNO ₃ , the major products formed are:
Options
- AH ₃ PO ₃ , NO ₂ and H ₂ O
- BH ₃ PO ₄ , NO and H ₂ O
- CH ₃ PO ₄ , NO ₂ and H ₂ O
- DPH ₃ , NO ₂ and H ₂ O
Correct answer
C. H ₃ PO ₄ , NO ₂ and H ₂ O
Step-by-step solution
Concentrated nitric acid acts as a strong oxidizing agent. It oxidizes non-metals like phosphorus to their highest stable oxyacids. White phosphorus ( P ₄ ) is oxidized to orthophosphoric acid ( H ₃ PO ₄ ), while concentrated HNO ₃ is reduced to nitrogen dioxide ( NO ₂ ). The balanced chemical equation is: P ₄ + 20 HNO ₃ 4 H ₃ PO ₄ + 20 NO ₂ + 4 H ₂ O Answer: H ₃ PO ₄ , NO ₂ and H ₂ O