Type of compound:Aldehyde

Alcohol

Amine

Ketone

Identify an Unknown

Procedure

1. Physical PropertiesMelting point or boiling point

2. Functional Group

Infrared spectrum

NMR Spectrum

Solubility

Classification Tests

3. Solid Derivative

Measure boiling point of liquids

Distill your unknown and note the boiling point

If can’t distill or not enoughsample use this technique.

Functional GroupCarbonyl Group (1650 - 1725 cm-1)?

Yes No

AldehydeKetone

NMR

Aldehyde Ketone+ -

AlcoholAmine

BroadOH in IR

Yes NoAlcohol Amine

(Basic?)3700 - 4000 cm-1

YesPrimary or Secondary

NoTertiary

2,4-dinitrophenylhydrazine test

NH2NH

NO2

NO2

Aldehyde or ketone

R-C-R

O+ NH2NH

NO2

NO2

NNH

NO2

NO2CR

R

2,4-dinitrophenylhydrazone

C

ONH2R C

OH

NHR

NRC

Iodoform TestReagent: NaOH and I2 (NaOI)

CCH3

O

RI2, NaOH

RCOOH + CHI 3Yellow

CCH3

O

RI2, NaOH

RCOOH + CHI3Yellow

Iodoform Test

CHCH3

OH

RI2, NaOH

RCOOH + CHI3Yellow

Ceric Nitrate Test for Alcohols

(NH4)2Ce(NO3)6 + ROH

(NH4)2Ce(NO3)5OR

+ HNO3

Amines

1. Odor

2. If not soluble in water they maydissolve in dilute aqueous acid (HCl).

3. Water solutions of amines arebasic to litmus.

Hinsberg Test for Amines

SO2Cl

Benzenesulfonyl Chloride

Hinsberg Test for Amines

Primary: Soluble. PPT if add HClSecondary: Insoluble

Tertiary: Tends not to react

DerivativesAldehydes and Ketones

1. 2,4-dinitrophenylhydrazone

2. Semicarbazone

NH2NHC

O

NH2

semicarbazide

+ RC

O

R NNHCNH2CR

RO

semicarbazone

Alcohol Derivative

O2N

O2N

C ClO

O2N

O2N

C OROROH

3,5-dinitrobenzoyl chloride

3,5-dinitrobenzoate

Amine DerivativesPrimary and Secondary Amines

CO

Cl + RNH2 CO

NHR

Benzoyl Chloride Benzamide

SO2Cl + RNH2 SO2NHR

Benzenesulfonyl Chloride Benzenesulfamide

Sample Unknown

B.p. =198-200o

DNP = 231-235o

C

O

CH3

acetophenone

Sample Unknown

B.p. = 80 - 85o

3,5-dinitrobenzoate= 119 - 121o

CCH3 CH3

H

OH

isopropyl alcohol

B.p = 106o

3,5-dinitrobenzoate85o

CH2OHCH

CH3

CH3

isobutyl alcohol

B.p. = 160o

3,5-dinitrobenzoate:108-110o

OH

H

cyclohexanol

B.p. = 155-157o

2,4-DNP = 158 -160o

O

cyclohexanone

B.p. = 180 -183o

Benzenesulfonamide110 - 112o

Benzamide 160 - 163o

NH2

aniline