exp 2 alcohols and phenols

Ethyl Alcohol

Isopropyl Alcohol

Tert-Butyl alcohol

Phenol

Salicylic acid

Resorcinol

Test Compounds 6

Ethyl Alcohol Chromic Acid Test

color changes from orange to green (oxidized to acetic acid)

Isopropyl Alcohol Chromic Acid Test

color changes from orange to green (oxidized to acetone)

Tert-Butyl alcohol Chromic Acid Test

No color change (no oxidation occurs)

Ethyl Alcohol Lucas Test

does not react at room temperature but when heated, solution turns cloudy.

Isopropyl Alcohol Lucas Test

In 5 mins, solution appears cloudy. In 10 mins, distinct organic layer appears. Alkyl Halide is visible at room temperature as a milky suspension then turns to an oily layer.

Tert-Butyl alcohol Lucas Test

Solution remains clear, no precipitate

Ethyl Alcohol Iodoform Test

Foul smelling yellow precipitate (iodoform) formation - positive

Ethyl Alcohol Iodoform Test

Yellow precipitate (iodoform) formation - positive

Tert-Butyl alcohol Iodoform Test

Solution remains clear, no precipitate

Phenol Ferric Chloride

Violet color is observed.

Salicylic acid Ferric Chloride

Violet color is observed.

Resorcinol Ferric Chloride

Blue color is observed.

Phenol Bromine Water

Bromine water is decolorized, white precipitate forms.

Salicylic acid Bromine Water

Bromine water is decolorized, a white or pale yellow precipitate may form.

Chromic Acid Test

Lucas Test

Iodoform Test

Ferric Chloride

Bromine Water

Modified Liebermann’s Test

Test/Reagents

Resorcinol Bromine Water

Bromine water is decolorized, white precipitate appears.

Phenol Modified Liebermann’s Test NaNO₂, H₂SO₄

Solution becomes yellow, but changes to blue due to H₂SO₄.

Phenol Modified Liebermann’s Test Ice water

Blue solution turns into red.

Phenol Modified Liebermann’s Test NaOH

The red solution reverts back to blue.

3° < 2° < 1°

Chromic Acid Test Order of Reactivity

1° < 2° < 3°

Lucas test (ZnCl₂ in HCl) Order of Reactivity

reaction of ethanol in chromic acid test

3CH3​CH2​OH+2H2​CrO4​+6H+⟶3CH3​COOH+2Cr3++5H2​O

reaction of tert-butanol in Lucas test

(CH3​)3​COH+HCl⟶(CH3​)3​CCl+H2​O

substitution reaction

What type of reaction occurs between bromine (in water) and phenol: addition or substitution?

substitution

A _ reaction occurs between bromine (in water) and phenol.

Phenol

_ is highly reactive towards this electrophilic substitution because of the electron-donating effect of the hydroxyl group - increasing electron density.

electrophilic substitution

Phenol is highly reactive towards this _ because of the electron-donating effect of the hydroxyl group - increasing electron density.

based on the electron-donating ability

Explain the following order of reactivity toward electrophilic bromine: C₆H₅O⁻ > C₆H₅OH >> C₆H₆

C₆H₅O⁻ (phenoxide ion)

_ is highly reactive because the negative charge strongly activates the ring for electrophilic substitution.

C₆H₆ (benzene)

_ has no activating group and is the least reactive.

C₆H₅OH (phenol)

_ has an -OH group that activates the ring via resonance but is less reactive than phenoxide.