NEET2026ChemistryChapterActual
In the qualitative analysis of an organic compound, carbon and hydrogen are detected by heating the compound with reagent X . The presence of hydrogen is confirmed when the evolved gas is passed over anhydrous Y , which turns blue. Identify X and Y .
Options
- AX = CuO , Y = CuSO₄
- BX = Na , Y = FeSO₄
- CX = CuO , Y = Ca(OH)₂
- DX = AgNO₃ , Y = CuSO₄
Correct answer
A. X = CuO , Y = CuSO₄
Step-by-step solution
In the qualitative analysis of an organic compound, carbon and hydrogen are detected by heating the compound with copper(II) oxide ( CuO ). Carbon is oxidized to carbon dioxide ( CO₂ ) and hydrogen is oxidized to water ( H₂O ). C + 2 CuO CO₂ + 2 Cu 2 H + CuO H₂O + Cu The presence of hydrogen is confirmed by passing the evolved water vapor over anhydrous copper(II) sulfate ( CuSO₄ ), which is white. It turns blue due to the formation of copper(II) sulfate pentahydrate ( CuSO₄ 5H₂O ). CuSO₄ (white) + 5 H₂O CuSO₄ 5H₂O