ORGANIC CHEMISTRY II LAB#8

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.

Oliec acid: is the unsaturated fatty acid.

CH3(CH2)16COOH

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

lipidGlycerol Oliec acid stearic acid

viscous liquid Oil Oil State

colorless Yellow colorless

color

odorless Characteristic odor

Characteristic odor

odor

17.8 °C -11 °C 69 °C Melting point

Glycerol is miscible with

water and partially soluble in

organic solvents

insoluble in water, it is soluble in organic

compounds

insoluble in water, it is soluble in organic

compounds

Solubility

Chemical tests

Chemical test

general

1\Grease spot test

2\Emulsion of lipid

3\Saponification test

Specific 4\Copper acetate test

Chemical 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 :

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”

(a specific test)

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