MCQ
Which one of the following gives iodoform test
  • A
    Formaldehyde
  • Ethyl alcohol
  • C
    Benzyl alcohol
  • D
    Benzaldehyde

Answer

Correct option: B.
Ethyl alcohol
b
(b) The compound having $\alpha-$ hydrogen will give iodoform test. Ethyl alcohol and secondary alcohols also give positive iodoform test because by the action of halogens in alkaline medium, they are oxidesed to acetaldehyde and methyl ketones respectively.

$C{H_3}C{H_2}OH\mathop {\xrightarrow{{{I_2}}}}\limits_{NaOH} C{H_3}CHO\mathop {\xrightarrow{{{I_2}}}}\limits_{NaOH} C{I_3}CHO$ $\xrightarrow[{NaOH}]{{{H_2}O}}CH{I_3} + HCOONa$

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