Question

Which of the following compounds does not give a positive iodo-form test?

• A. Ethanol
• B. Acetone
• C. Acetaldehyde
• D. Methanol

Answer 1

The correct option is D Methanol

$\text{Positive iodoform fest is given by methyl-ketone.}$

$(R-CO-C{H}_3)$

$\text{So, among the following}$

$\begin{array}{c}{CH}_3{CH}_{2}OH,{CH}_3-CO-{CH}_3,{CH}_3-CHO\text{and}\\ {CH}_{3}OH\end{array}$

$\begin{array}{c}\text{only methanol does not give positive iodoform test.}\\ \text{Note that, alcohols with structure}R-CH\left(OH\right)-{CH}_3\text{can also}\\ \text{give this test.}\end{array}$