Question

Which of the following does not give iodoform test?

Options

• Ethanol

• Ethanal

• Propan-2-ol

• Butan-1-ol

Answer 1

Butan-1-ol

Explanation:

$$\underset{\mathrm{Ethanol}}{\mathrm{CH}{\phantom{A}}_3\mathrm{CH}{\phantom{A}}_2\mathrm{OH}}+4\mathrm{I}{\phantom{A}}_2+6\mathrm{NaOH}\stackrel{\mathrm{\Delta }}{\to }\mathrm{CHI}{\phantom{A}}_3+\mathrm{HCOONa}+5\mathrm{NaI}+5\mathrm{H}{\phantom{A}}_2\mathrm{O}$$

$$\mathrm{CH}{\phantom{A}}_3\mathrm{CHO}+3\mathrm{I}{\phantom{A}}_2+4\mathrm{NaOH}\stackrel{\mathrm{\Delta }}{\to }\mathrm{HCOONa}+\mathrm{CHI}{\phantom{A}}_3+3\mathrm{NaI}+3\mathrm{H}{\phantom{A}}_2\mathrm{O}$$

$$\begin{array}{c}\mathrm{OH}\phantom{........................................................}\\ |\phantom{..........................................................}\\ \underset{\mathrm{Propane}\text{-}2\text{-}\mathrm{ol}}{\mathrm{CH}{\phantom{A}}_3-\mathrm{CH}-\mathrm{CH}{\phantom{A}}_3}+4\mathrm{I}{\phantom{A}}_2+6\mathrm{NaOH}\stackrel{\mathrm{\Delta }}{\to }\mathrm{CHI}{\phantom{A}}_3+5\mathrm{NaI}+\mathrm{CH}{\phantom{A}}_3\mathrm{COONa}+5\mathrm{H}{\phantom{A}}_2\mathrm{O}\end{array}$$

$$\mathrm{CH}{\phantom{A}}_3-\mathrm{CH}{\phantom{A}}_2-\mathrm{CH}{\phantom{A}}_2-\mathrm{CH}{\phantom{A}}_2-\mathrm{OH}+\mathrm{I}{\phantom{A}}_2+\mathrm{NaOH}⟶\mathrm{No}\mathrm{reaction}$$