Question

Which of the following compounds will react with sodium hydroxide solution in water?

• A. $C_2{H}_{5}OH$
• B. $C_6{H}_{5}OH$
• C. $(C{H}_3{)}_{3}COH$
• D. $C_6{H}_{5}C{H}_{2}OH$

Answer 1

The correct option is B $C_6{H}_{5}OH$

$\text{Understanding the concept of reactivity of given species with sodium hydroxide}$

The alcohol which can form a more stable anion than hydroxide ion will react with sodium hydroxide in water.

$\text{Analysing the options}$

Option (A)

Phenoxide ion formed by phenol $\left(C_6{H}_{5}OH\right)$ is more stable than hydroxide ion because negative charge on phenoxide ion will be delocalized on benzene ring. So, phenol will react with sodium hydroxide solution in water.


Option (B)

Conjugate base of benzyl alcohol will be:


Here, negative charge will not be stabilized by resonance thus it will be comparatively less stable and benzyl alcohol will not react with sodium hydroxide.

Option (C)

Conjugate base of $(C{H}_3{)}_{3}COH$ will be:


This will be less stable than hydroxide ion due to $+I$ effect of $tert-$butyl group. So, $(C{H}_3{)}_{3}COH$ will also not react with sodium hydroxide.

Option (D)

Conjugate base of ethanol will be:

$C_2{H}_5{O}^{-}$

It will be less stable than hydroxide ion due to $+I$ effect of ethyl group. So, ethanol too will not react with sodium hydroxide.

Hence the correct answer is option $\left(A\right)$.