Question

Oxidation of organic compound $'A'$ with $Na_2Cr_2O_7$ and $H_2SO_4$ gives compound $'B'$, which on reduction with $H_2$ in the presence of Ni catalyst gives ethyl alcohol. Give the name of compound $'A'$.

• A. ethanal
• B. ethanol
• C. ethanoic acid
• D. ethene

Answer 1

Answer: (B)

ethanol

Answer 2

${ A ->[Na_2Cr_2O_7 / H_2SO_4][{[O]}] B->[H_2 / Ni] Ethyl \, alcohol }$ Compound Bon reduction with $H_2$ in the presence of Ni gives ethyl alcohol, it means compound B is ethanal or ethanoic acid; because aldehyde or acid on reduction gives primary alcohol. Again, compound B is obtained by the oxidation of A, it means A is ethanol, because primary alcohol on oxidation gives aldehyde or acid.