ORGANIC CHEMISTRY II
LAB#8
Lab # 8
Princess Norah Bint Abdulrahman
University
Collage of pharmacy
Pharmaceutical Chemistry Department
lipid




Lipids consist of glycerol and fatty acids "tails".
A lot of lipids function as long-term energy storage.
One gram of fat stores more than twice as much
energy as one gram of carbohydrates.
Lipids are also an important component of the cell
membrane.
lipid

stearic acid: is the saturated fatty acid.
CH3(CH2)16COOH

Oliec acid: is the unsaturated fatty acid.
CH3(CH2)7CH=CH(CH2)7COOH
lipid


Glycerol (acylglycerols) :
They are esters formed from glycerol and fatty
acids.
It can be produced by saponification of fats.
Glycerol
Acylglycerol
Saponification
PHYSICAL PROPERTIES
lipid
stearic acid
Oliec acid
Glycerol
State
Oil
Oil
viscous liquid
color
colorless
Yellow
colorless
odor
Characteristic odor
Characteristic odor
odorless
Melting point
69 °C
-11 °C
17.8 °C
Solubility
insoluble in water, it
is soluble in organic
compounds
it insoluble in water, Glycerol is miscible
is soluble in organic
with water and
compounds
partially soluble in
organic solvents
Chemical tests
Chemical test
1\Grease spot test
general
2\Emulsion of lipid
3\Saponification
test
Chemical test
Specific
4\Copper acetate
test
1\ Grease spot test:


To a small amount of lipid add 3ml ether in test
tube then pour the mixture in a filter paper.
Result: lipid leave translucent spots (grease spots)
on the filter paper.
2\ Emulsion of lipid:

Pour 2ml of ethanol into a test tube. Add one drop
of oil to the ethanol in the test tube. Cover the open
end of the test tube with your thumb and shake the
test tube thoroughly to mix the contents. Pour the
mixture into the second test tube containing about
2ml of water.
3\ Saponification test:

Add 1ml of oil to 5ml of NAOH, heat content of the
test tube on a water bath the oil will transfer to
soap, remove the test tube from the water bath and
add 5ml water and mix.
4\ Copper acetate test : (a specific test)

In a test tube add small amount of oil + 3ml of
ether + 3ml of copper acetate then shake once.
Result:
 glycerol : 2 layer “ the above layer is ether and the
other layer is copper acetate”
4\ Copper acetate test:


Unsaturated fatty acid (oleic acid): 2 layer “ the
upper layer colored green and the lower layer
colored blue”
Saturated fatty acid (stearic acid): 2 layer
“Appearance of white blue ppt. at the bottom of
the upper layer”.
Copper acetate test:
Thank you