Question

Which of the following organic compounds answers to both iodoform test and Fehling's test?

• A. ethanol
• B. methanal
• C. ethanal
• D. propanone

Answer 1

Answer: (C)

The compound which contains $COC{H}_3$ group in its structure, give positive iodoform test and the compound which contains $CHO$ group give positive Fehling test. In ethanal,$C{H}_{3}CHO$ both the groups are present, hence it responds to both iodoform test and Fehling’s test.

$C{H}_{3}CHO+I_2+NaOH⟶\underset{\text{Iodoform }}{CH{I}_3}+NAI+H_{2}O$

$C{H}_{3}CHO+\underset{\text{Fehling’s Soliution}}{Cu(OH{)}_2}⟶C{H}_{3}COOH+\underset{\text{Red ppt }}{C{u}_{2}O\downarrow }+2H_{2}O$