Question

A compound that shows positive iodoform test is

• A. 2 -pentanone
• B. 3-pentanone
• C. 3 -pentanol
• D. 1-pentanol

Answer 1

Answer: (A)

Iodoform test with sodium hypoiodite is used for the detection of $C{H}_{3}CO$ group or $C{H}_{3}CH(OH)$ group which produces $C{H}_{3}CO$ group on oxidation.
Iodoform reaction with the given compounds are as follows :

If gives positive iodoform test due to the presence of $C{H}_{3}CO$ group.

It gives negative iodoform test.

It doesn't give positive iodoform test.
(d) $\underset{\text{1 - pentanol}}{C{H}_{3}C{H}_{2}C{H}_{2}C{H}_{2}C{H}_{2}OH}+I_2/NaOH$
$\stackrel{H^{+}/H_{2}O}{\to }$ no reaction
It also gives negative iodoform test.