Question

iodoform test is not given by: a) 2- pentanol b) 3 - pentanol. c). ethanol. d) ethanal

Answer 1

the option is the d

Answer 2

Explanation:

Iodoform test is defined as the test used to determine the presence of a carbonyl group in a compound.

Formation of yellow precipitate by reaction of iodine with a methyl ketone base is known as iodoform test.

And, compounds with chemical formula $R-COCH_{3}$ and alcohols with structure $CH_{3}CH(OH)R$ will show positive iodoform test.

Chemical formula of 2-pentanol is $CH_{3}CH(OH)CH_{2}CH_{2}CH_{3}$. It contains $CH_{3}CH(OH)R$ group so, it will show positive iodoform test.

Chemical formula of 3-pentanol is $CH_{3}CH_{2}CH(OH)CH_{2}CH_{3}$. It does not contain $CH_{3}CH(OH)R$ group so, it will show negative iodoform test.

Chemical formula of ethanol is $CH_{3}CH_{2}OH$. It contains $CH_{3}CH(OH)R$ group so, it will also show positive iodoform test.

Chemical formula of ethanal is $CH_{3}CHOH$. It contains $R-COCH_{3}$ group so, it will also show positive iodoform test.

Thus, we can conclude that out of the given options 3 - pentanol will not give iodoform test.