Question

An organic compound A on heating with conc. H₂SO₄ forms a compound B which on addition of one mole of hydrogen in the presence of nickel forms C.One mole of C on combustion forms 2 moles of CO₂ and 3 moles of H₂O.Identify the compounds A,B,C and write the equation for the reactions involved.

Answer 1

2 moles of CO₂ and 3 moles of H₂O are given out on combustion of 1 mole of carbon.
The hydrocarbon will be ethane (C₂H₆) . Therefore , 'C' is ethane.
2C₂H₆ + 7O₂ $\to$4CO₂ + 6H₂O
Now , B will add 1 mole of hydrogen in presence of nickel to form 'C'.
CH₂=CH₂ + H₂ $\stackrel{\text{Ni}}{\to }$ CH₃-CH₃
'B' is ethene (C₂H₄) and 'C' is ethane (C₂H₆) .
Now , 'A' on heating with concentrated H₂SO₄ will give B.
C₂H₅OH $\stackrel{\text{Conc}.{\text{H}}_{2}S{O}_4}{\to }$ C₂H₄ + H₂O
Therefore , 'A' is (ethanol) C₂H₅OH .