Phenols and Azo Dyes

Which of the formulas below gives the condensed structural formula of phenol?

• C₆H₅OH

• C₅H₆OH

• C₆H₅NH₂

• C₆H₅NO₂

The -OH group attached to the benzene ring in phenol has an electron _________ effect, resulting in the ring being much more reactive.

• withdrawing

• donating

• resonance

• neutral

The benzene ring in phenols undergoes a(n) ___________ reaction.

• polymerization

• addition

• substitution

• acylation

The activated benzene ring in phenols is attacked by a(n) ___________

• nucleophile

• catalyst

• carbocation

• electrophile

The group attached to the benzene ring in phenols does NOT have a directing effect in which of the following positions?

• 3

• 2

• 4

• 6

When phenol is treated with excess bromine water, which of the following products is produced in the reaction?

• 3-bromophenol

• bromophenol

• 2,4-dibromophenol

• 2,4,6-tribromophenol

When aqueous bromine reacts with phenol, a rapid decolorization of the yellow-orange color occurs. Identify which of the following below indicates the color of the precipitate formed from the reaction of aqueous bromine and phenol.

• pink precipitate

• blue precipitate

• white precipitate

• brown precipitate

During the reaction of aqueous bromine and phenols, two products are formed from the reaction. One of the product is in the form of a solid, the other is a gaseous fume. Identify which of the following is a gaseous product of this reaction.

• Water

• hydrogen bromide

• hydrogen gas

• bromophenol

Due to the acidic character of phenols, phenols react with sodium hydroxide to form

• phenyl hydroxide

• sodium oxide

• sodium phenoxide

• phenoxide ion

Phenols are more acidic than alcohols because

• phenoxide ion is stabilized by resonance

• phenoxide ion does not exhibit resonance

• phenols are more soluble in polar solvents

• alcohols do not lose H atoms at all