Question

Phenol is a weaker acid than ethanol.
True or False

Answer 1

Hint: We have to know that the chemical species whose pH value lies between $0 - 7$ is considered as acidic in nature. Generally acidic compounds possess a sour taste. In early days acid was defined as a substance which tastes sour, reacts with metal and turns blue litmus to red.

Complete answer:
We need to remember that both alcohols and phenol are weak acids, the alcohols are less acidic than phenol because it is very tough to remove ′ \[{H^ + }\]′ ions from alcohol. Phenol can lose ions easily because phenoxide ions are stabilized to some extent. This is as the negative charge on the oxygen atom is delocalized around the ring. The acidic substance has the tendency to produce \[{H^ + }\] ions when dissolved in water. Both phenol and ethanol are weak acids. However, the acidity of phenol is more than that of ethanol. This is because after losing a proton, the phenoxide ion undergoes resonance and gets stabilized whereas ethoxide ion does not. Phenols react with aqueous sodium hydroxide to produce phenoxide ions. This indicates that the acidity of phenols is higher in comparison to the alcohols. The phenoxide ion is stabilized by the delocalization of negative charge due to the resonance in the benzene ring.
Phenol is a stronger acid than ethanol. This is due to the resonance stabilization of the phenolate ion which is produced after deprotonation.

Note:
We need to know that the phenol is more acidic than aliphatic compounds containing \[O{H^ - }\] group due to resonance stabilization of phenoxide ion by the aromatic ring. In this way negative charge of oxygen atoms is delocalized on ortho and para carbon atoms. Due to which stability increases.