unkwn2
DESCRIPTION
Unkwn2TRANSCRIPT
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Type of compound:Aldehyde
Alcohol
Amine
Ketone
Identify an Unknown
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Procedure
1. Physical PropertiesMelting point or boiling point
2. Functional Group
Infrared spectrum
NMR Spectrum
Solubility
Classification Tests
3. Solid Derivative
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Measure boiling point of liquids
Distill your unknown and note the boiling point
If cant distill or not enoughsample use this technique.
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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
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2,4-dinitrophenylhydrazine test
NH2NH
NO2
NO2
Aldehyde or ketone
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R-C-R
O+ NH2NH
NO2
NO2
NNH
NO2
NO2CR
R
2,4-dinitrophenylhydrazone
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CONH2R C
OH
NHR
NRC
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Iodoform TestReagent: NaOH and I2 (NaOI)
CCH3
O
RI2, NaOH RCOOH + CHI 3
Yellow
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CCH3
O
RI2, NaOH RCOOH + CHI3
Yellow
Iodoform Test
CHCH3
OH
RI2, NaOH RCOOH + CHI3
Yellow
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Ceric Nitrate Test for Alcohols
(NH4)2Ce(NO3)6 + ROH
(NH4)2Ce(NO3)5OR
+ HNO3
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Amines
1. Odor
2. If not soluble in water they maydissolve in dilute aqueous acid (HCl).
3. Water solutions of amines arebasic to litmus.
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Hinsberg Test for Amines
SO2Cl
Benzenesulfonyl Chloride
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Hinsberg Test for Amines
Primary: Soluble. PPT if add HClSecondary: Insoluble
Tertiary: Tends not to react
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DerivativesAldehydes and Ketones
1. 2,4-dinitrophenylhydrazone
2. Semicarbazone
NH2NHC
O
NH2semicarbazide
+ RC
O
R NNHCNH2CR
RO
semicarbazone
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Alcohol Derivative
O2N
O2N
C ClO
O2N
O2N
C OROROH
3,5-dinitrobenzoyl chloride
3,5-dinitrobenzoate
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Amine DerivativesPrimary and Secondary Amines
CO
Cl + RNH2 CO
NHR
Benzoyl Chloride Benzamide
SO2Cl + RNH2 SO2NHR
Benzenesulfonyl Chloride Benzenesulfamide
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Sample Unknown
B.p. =198-200o
DNP = 231-235o
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CO
CH3
acetophenone
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Sample Unknown
B.p. = 80 - 85o
3,5-dinitrobenzoate= 119 - 121o
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CCH3 CH3
H
OH
isopropyl alcohol
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B.p = 106o
3,5-dinitrobenzoate85o
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CH2OHCH
CH3
CH3
isobutyl alcohol
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B.p. = 160o
3,5-dinitrobenzoate:108-110o
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OH
H
cyclohexanol
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B.p. = 155-157o
2,4-DNP = 158 -160o
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Ocyclohexanone
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B.p. = 180 -183o
Benzenesulfonamide110 - 112o
Benzamide 160 - 163o
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NH2
aniline