P.l alcohols and phenols

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Alcohols and Phenols

ALCOHOLa compound that contains an -OH

(hydroxyl) group bonded to a tetrahedral carbon.

Methanol (CH3OH): simplest alcohol

CHEMICAL PROPERTIES

An alcohol is made up of a chain of carbons and hydrogen, where an –OH molecule attaches to where a Hydrogen molecule is supposed to be attached to a Carbon.

The position of the OH group has little effect on the chemical properties except in their response to mild oxidizing agents.

USES OF ALCOHOLS

Disinfectants Solvents Liquor High efficiency fuels Used to synthesize

other organic compounds

FungicidesCosmeticsUsed to make vinegarUsed in the manufacturing of plastics

USES (CONTINUED)

Methanol- Solvent for fats, oils, and resins. Manufacture of dyes, antifreeze, and plastics.

Ethanol- Solvent for paints, glues, pharmaceuticals, and explosives.

Cyclohexanol-Intermediate in making chemicals used in nylon manufacture.

DANGEROUS PROPERTIES

Very combustible Poisonous to an extent Addiction Bodily damage caused by exposure

Alcohol products

Product % of Ethyl Alcohol

BEER 3.5-9

WINE 12

BRANDY 40-45

WHISKEY 45-55

RUM 45

Ethanol

Toxic to humans Acute poisoning kills several hundred a

year (drinking contests) Long term poisioning

Most serious drug problem in US 40 times more addicts than heroin

Isopropyl Alcohol

Rubbing alcohol Rapid evaporation Antiseptic More toxic than ethanol, but induces

vomitting Used for the manufacture of acetone

PHYSICAL PROPERTIES

Boiling point increases as MW increases. Solubility in water decreases as MW (due to

increase in C-H) increases. Alcohols are semi-polar molecules

C-O and O-H bonds: polar covalent C-H bonds: non-polar covalent

Phenol

The antiseptic property of phenol was discovered in 1865 by Joseph Lister, a physician in Scotland.

Listerine, named after him, contains phenol as the active ingredient.

Today, over two million tons of phenol are made each year in the US alone.

Phenol is used for resins, glue to make plywood, plastics, and pharmaceuticals. OH

Phenols Ar-OH

Phenols are compounds with an –OH group attached to an aromatic carbon. Although they share the same functional group with alcohols, where the –OH group is attached to an aliphatic carbon, the chemistry of phenols is very different from that of alcohols.

Experimental Result1 ml water + Solubility pHMethanol Miscible BasicEthanol Miscible Basic

Propanol Miscible BasicN-butyl Immiscible BasicN-amyl Immiscible BasicPhenol Immiscible Acidic

CHEMICAL PROPERTIES

Reaction with Lucas Reagent Lucas reagent: ZnCl2 in HCl Positive result: formation of turbidity or

two layers General equation:

R - OH R - Cl + H2OZnCl2 ,HCl

Experimental Result

most reactive

more reactive

least reactive

Reactivity

turbidity

3o-butyl alcohol

turbidity

2o-butyl alcohol

turbidity

n-butyl alcohol

Product/s formedVisible

(+) ResultCompound

Ethanol(Ethyl alcohol)

1-Propanol(Propyl alcohol)

2-Propanol(Isopropyl alcohol)

1-Butanol(Butyl alcohol)

2-Butanol(sec-Butyl alcohol)

2-Methyl-1-propanol(Isobutyl alcohol)

2-Methyl-2-propanol(tert-Butyl alcohol)

Cyclohexanol(Cyclohexyl alcohol)

2-chloro-2-methylpropane

2-chlorobutane

I-chlorobutane

Lucas Test

Alcohols: 2 layers formed, 2nd layer turbidity

Phenol: 1st layer turbidity

Lucas Test

Used to classify low molecular weight alcohols

no visible reaction at room temperature and cloudy only on heating: primary

solution turns cloudy in 3–5 minutes: secondary

solution turns cloudy immediately, and/or phases separate: tertiary

Oxidation

Oxidation by KMnO4

(dehydrogenation) Oxidizing agent:

Positive result: Decolorization with brown precipitation

Oxidation

Primary Produces an aldehyde Then goes through further oxidation to produce a

carboxylic acid Secondary

Produces a ketone Tertiary

No reaction Can’t break the carbon-carbon bond

Phenol Produces quinones

R - C - H + KMnO4

heatR - C - OH + MnO2 + KOH

R - C - R' R - C - R'

[O] R - C - R'

NO REACTION

Experimental Result

compound was not oxidized

compound was oxidized

Interpretation

Negative result

3o-butyl alcohol

decolorization with brown

precipitation

2o-butyl alcohol

decolorization with brown

precipitation

n-butyl alcohol

Product FormedVisible (+)

ResultCompound

3-Methylbutanal 2-Propenal(Acrolein)

Hexanal

butanalO

CH3COH

Acetaldehyde Acetic acid Ethyl isopropyl ketoneMethyl ethyl ketone

butanone

Iron chloride test

Used to detect phenols

The formation of a red, blue, green, or purple coloration indicates the presence of phenols

The ferric chloride test can be used to detect metabolites in urine in case of congenital metabolic problems or genetic diseases

Results

Sample Color Indication N-butyl Yellow Negative Phenol Blue Positive

Esterification Reactants: alcohol + carboxylic acid Product formed: ESTER Positive result: distinct fragrant odor General equation:

O O ιι ιι R-OH + R-C-OH R-C-O-R + H2O Alcohol Carboxylic acid Ester

CH3C-OHO

H-OCH2CH3H2SO4

CH3COCH2CH3

Ethanoic acid(Acetic acid)

Ethyl ethanoate(Ethyl acetate)

Experimental Result

Mint odor

Methanol

Paste glue odor

Phenol

ProductOdorAcid ReactantCompound

Methyl salicylate

END!!!

P.l alcohols and phenols

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