Estudiante

20/2/2013

Objectives:1) Recognizing substances containing fats through the solubilityAnd paper test. |
Mauricio Alberto Sánchez Vásquez | Identifying Lipids |Materials:
Eyedroppers (2)
Test tubes (4)
Manila Paper
Gasoline or ether
Water
Olive Oil
Cooking Oil
Margarine
Peanut
Potato Juice
Milk
Lard
ScissorsMatches
Alcohol burner
Sudan III
Red ink
Test tube rack

Procedure:
First we take two Test Tubes and we place 3ml of water in one and 3ml of gasoline or otherorganic solvent in the other.

Then we add 1 ml of oil to each tube and then we stir vigorously. We observed that the water and oil don’t mix, but gasoline yes, theymix but you can see some drops of oil.

Then we took a piece of Manila paper which allows us to see the translucent spot (semitransparent in presence of fats.)After we took the piece of Manila paper, we place a drop of water on it and in the other we place a drop of oil. We observed that the oil don’t expand meanwhile the wateryes.

Then we took 6 pieces of Manila paper for us to make the test by placing a drop of the other substances.

SUBSTANCES | TRANSLUCENT SPOT | PRESENCE OF |LIPID |
| | Yes | No |
Potato Juice | No | | No |
Milk | No | | No |
Oil | Yes | Yes | |
Margarine | Yes | Yes | |
Peanut | Yes | Yes | |
Lard | Yes| Yes | |

Analysis and Interpretations
1) How did you prove the presence of fats?
A/: We prove it if the manila paper had a translucent spot

2) Which of thefollowing foods contain lipids?

RICE – NO
PORK MEAT – YES
WHITE BREAD – NO
BACON – YES
HAM – YES
MARGARINE – YES
APPLE – NO
CORN – YES
CHICKEN MEAT – YES