ORGANIC CHEMISTRY ||
T.A HAYA S ALSUBAIE
Pharmaceutical chemistry department
Pharmacy college
Princess Nora University
ALDEHYDES AND KETONES
OBJECTIVES
Write the functional groups of aldehydes and ketones.
Determine chemical and physical properties of aldehydes
and ketones.
Perform chemical tests to distinguish between aldehydes
and ketones.
INTRODUCTION
 Aldehydes and ketones are simple compounds which contain a
carbonyl group . (c=o)
(R=alkyl or aryl )
Aldehyde
• Has at least one hydrogen atom attached
directly to carbonyl carbon.
• Hydrogen atom makes aldehydes very easy
to oxidize .
ketone
• Has two alkyl(or aryl) groups attached to
carbonyl carbon.
• Ketones don't have that particular
hydrogen atom,
resistant to oxidation.
• Only very strong oxidizing agents like
(potassium permanganate solution) oxidize
ketones.
PHYSICAL PROPERTIES OF ALDEHYDE
Formaldehyde & Acetaldehyde
State
Liquid
color
colorless
odor
pungent odor
flammability
Blue non-smoky flame
solubility
completely miscible with water
effect on LP
neutral
structure
formaldehyde
acetaldehyde
PHYSICAL PROPERTIES OF KETONES
Acetone
State
Liquid
color
colorless
Odor
characteristic odor
Flammability
Blue non-smoky flame
Soloubility
completely miscible with water
effect on L.P
Neutral
Structure
Chemical test
Specific test
General test
Oxidation test
Tollen’s
test
Schiff’s
reagent
Nanitroprussid
Fehling test
Iodoform
test
Salicylic
acid test
CHEMICAL TESTS
General Test:
 OXIDATION TESTS:
 1-Tollens’ silver mirror test:
procedure: 1 ml of ald. or ket. + 1 ml of Tollens’
reagent ;then warm in water bath for 2-5 min.
ALDEHYDE
SILVER Mirror
KETONE
NO Reaction
TOLLENS’ SILVER MIRROR TEST:
Acetaldehyde
Acetone
Formaldehyde
CHEMICAL TESTS
General Test:
OXIDATION TESTS:
2) Fehling test:
procedure: 1 ml of ald. or ket. + 1 ml of Fehling reagent A&B
then warm in water bath for 2-5 min.
aldehyde
Rapidly change in blue color
Acetone
No reaction
FEHLING TEST
Acetaldehyde
Formaldehyde
Acetone
CHEMICAL TESTS
General Test:
Schiff test:
 procedure: 1 ml of ald. or ket. + 2 drops of Schiff reagent.
Aldehyde
Ketone
Magenta color
Color slightly appear
SCHIFF TEST:
Acetone
Acetaldehyde
Formaldehyde
CHEMICAL TESTS
Specific tests:
1) Na-nitroprussid:
 procedure: 1 ml of ald. or ket. + 1 ml of Na- nitroprussid + 1 ml of 10%
NaOH.
Formaldehyde
Acetaldehyde
Acetone
No reaction
Red color
Red color
NA-NITROPRUSSID:
Acetone
Acetaldehyde
Formaldehyde
CHEMICAL TESTS:
Specific tests:
Iodoform test:
 procedure: 1 ml of ald. or ket. + 3 ml of 30% NaOH+ 1 ml of I2 solution
then warm in water bath for 2-5 min.( add more than 1 ml of I2 if you
need )
Formaldehyde
No reaction
Acetaldehyde
Yellow ppt.
acetone
Yellow ppt.
IODOFORM TEST
Acetaldehyde
Formaldehyde
Acetone
CHEMICAL TESTS:
Specific tests:
Salicylic acid :
 procedure: 1 ml of formaldehyde + few amount of
salicylic acid + 2 drops of conc. H2SO4.
Formaldehyde
Crimson red color
SALICYLIC ACID TEST
Formaldehyde
PRE-LAB QUESTIONS
 Give a structure of a compound that contains the following functional
groups:
- Aldehyde
- Ketone
 Why can distinguish between an aldehyde and a ketone using Tollen’s
Reagent ?
LAB SAFETY
THANK YOU ..