P8 SOAP

P8 SOAP

OBJECTIVE

Understand the saponification reaction and produce soap.

MATERIAL

·         600mL Beaker

·         Glass road

·         Goggles

·         Gloves

·         Clock glass

·         Spatula

·         Bunsen burner

·         NaOH

·         Water (always distilled)

·         Oil

PROCEDURE

We have made three experiments, that they are differenced in the quantities of oil and distilled water.

First experiment

MATERIAL: 500 mL of oil, 183 g of distilled water, 63 g NaOH, 35 mL of an essence, spatula and an Erlenmeyer.

Procedure:  

1. Firstly, we have to weight out the necessary quantity of NaOH and then, we dissolve it with the distilled water.
2. Secondly, we add it in an Erlenmeyer and we mixed with oil.
3. Finally, we add the essence (it can be any essence).

Second experiment

MATERIAL: 50 mL of oil, 20 g NaOH, 80 g of distilled water.

1.     We make dissolution from NaOH and water. 
2.     From this mixture we only take 50 mL.
3.     Then we add the oil and we mix it. 
4.     Finally, we have to heat it. We can also add an essence.

Third experiment

MATERIAL:  20 g NaOH, 80 g distilled water, 2mL of oil.

Procedure:

1. We dissolve NaOH with distilled water.
2. In a test tube we have put 2mL of that dissolution and 2mL of Oil.
3. We have made two test tubes like this.
4. We can add an essence.
5. We hit it in a “Baño María” (Water Bath).

QUESTIONS 

• What is the soap?  Soaps are carboxylate salts with very long hydrocarbon chains.
• Which is the reaction that we have done? Soap can be made from the base hydrolysis of a fat or an oil. This hydrolysis is called saponification.
• Which capes we have produced? 2 layers. Above soap and the below layer is oil and glycerin that have’nt reacted yet.
• Formulate the reaction of it.

P6 STARCH

OBJECTIVES 

Reveal the presence of starch in different foods and in a plant and know why it appears in any of them.

MATERIAL 

·        A piece of Frankfurt

·        A piece of jam

·        A leaf

·        A piece of a potato

·        A watch glass

·        A knife

·        Wire gauze

·        A lab burner

·        Lugol.

·        A dropper.

·        Ethanol

PROCEDURE

THE LEAF’S PROCEDURE

·        We have to heat the leaf for 2 minutes.

·        Then we take the leaf and we put it inside a test tube with ethanol.

·        We come back to heat it for 10 minutes.

·        Then we bring it out from the tube and we put it in a watch glass.

·        We add it lugol.

THE FOOD’S PROCEDURE

·        We cut a part from a potato, from Frankfurt and from jam.

·        Then we put them all in a different watch glass.

·        And we add lugol to reveal the starch presence.

RESULTS: WHE WE ADD IODINE SOLUTION TO THE FOOD SAMPLES (POTATOE, FRANKFURT SAUSAGE AND JAM), POTATOE AND FRANKFURT SAUSAGE STAIN TO DARK PURPLE OR BLACK. IT DOESN’T HAPENS WITH JAM.

CONCLUSION: IODINE SOLUTION IS AN INDICATOR OF STARCH PRESENCE. POTATOE AND FRANKFURT SAUSAGE CONTAIN STARCH.

THE PRESENCE OF STARCH IS AN EVIDENCE THAT PHOTOSYNTESIS HAS OCCURRED. GLUCOSE, THE PRODUCTE OF IT, HAS CONVERTED TO STARCH. 

QUESTIONS

Which is the origin of the starch that you can see in the leaf?  Photosyntesis. 
Explain the significance of boiling the leaf in water? Interrupt the photosyntesis.

Explain the significance of boiling the leaf in ethanol? Extract the clorophyll. 
Explain the significane of rinsing the leaf in water? To eliminate any remains of colorophyll.

P7 LIPIDS PROPERTIES

OBJECTIVES

Test the solubility of lipids. Identify lipids in liquid compounds and understand what are an emulsion and the effect of detergents.

MATERIAL

·         Test tube rack

·         250 mL beaker

·         Water

·         6 test tubes.

·         Cellulose paper

·         Dropper

·         Scissors

·         Glass rod

·         Olive oil

·         Soap (detergent)

·         Milk with different fat content: full-cream, semi-skimmed and skimmed milk.

·         Soy juice

·         Petroleum ether

·         Ethanol

·         Sudan III

PROCEDURE

We have made four different experiments to identify lipids.

Solubility of lipids:

1. Clean and dry three test tubes. Write on the first: W (water); in the second: Ethanol (E); and in the third: PE (petroleum ether).
2. Add three drops of acid oleic to the three test tubes.
3. Add 1 ml of water in the tube W; add 1 ml of ethanol in the tube E and 1ml of petroleum ether in the PE.
4. Shake each test tube and record the solubility of each tube.

RESULTS:

WATER+OIL------- INSOLUBLE

ETER+OIL   --------- SOLUBLE

PE+ OIL------------ SOLUBLE

CONCLUSION: Lipids are insolubles in wàter but are soluble in apolar orgànic dissolvents.

Translucent mark:

1.  Cut to pieces (10cmx10cm) of cellulose paper.
2.  Put one drop of water in the first piece, you will see a translucent spot, wait and observe what is happening.
3.  Put one drop of olive oil in the other, you will see a translucent spot. Is that going to disappear, why?

 CONCLUSION: Fats will leave a glossy, oily residue when wiped on paper. When light falls upon paper, a part of it is transmitted, a part is scattered, a part is absorbed, and a part is reflected

Sudan III dye

1. Take the W test tub and add two drops of Sudan III.
2. Prepare four test tubes: 3 with milk, each of different fat content and the fourth with soy juice, observe the results.

RESULTS:

1-      SKIMMED MILK: The solution stain soft orange

2-      Semi-skimmed milk: The solution stain medium orange

3-      Whole milk: The solution stain reddish- Orange

4-      Soy juice: It doesn’t change the colour.

•          CONCLUSION: Sudan III is not soluble in water; it is, however, soluble in lipids. If lipids are present the Sudan III will stain them reddish-orange.

EMULSION

1.  Take the beaker of 250 mL and put 100mL of water.
2.  Add 1 mL of oil.
3.  With a glass rod stir the mixture and left it for 5 minutes. Observe what is happening.
4.  Add two drops of soap and then notice the different of both mixtures.

1. RESULTS:
   WATER AND OIL FORM A TEMPORARY EMULSION
   WATER , SOAP AND OIL FORM A PERMANENT EMULSION
   CONCLUSION:  SOAP IS A TENSOACTIVE THAT ELIMINATE THE SURFACE TENSION BETWEEN THE WATER MOLECULES, BY ONE HAND, AND THE SURFACE TENSION OF OIL. THEN THE MIXTURE IS HOMOGENEUS (PERMANENT EMULSION).

P6 STARCH

OBJECTIVES 

Reveal the presence of starch in different foods and in a plant and know why it appears in any of them.

MATERIAL 

·        A piece of Frankfurt

·        A piece of jam

·        A leaf

·        A piece of a potato

·        A watch glass

·        A knife

·        Wire gauze

·        A lab burner

·        Lugol.

·        A dropper.

·        Ethanol

PROCEDURE

THE LEAF’S PROCEDURE

·        We have to heat the leaf for 2 minutes.

·        Then we take the leaf and we put it inside a test tube with ethanol.

·        We come back to heat it for 10 minutes.

·        Then we bring it out from the tube and we put it in a watch glass.

·        We add it lugol.

THE FOOD’S PROCEDURE

·        We cut a part from a potato, from Frankfurt and from jam.

·        Then we put them all in a different watch glass.

·        And we add lugol to reveal the starch presence.

RESULTS: WHE WE ADD IODINE SOLUTION TO THE FOOD SAMPLES (POTATOE, FRANKFURT SAUSAGE AND JAM), POTATOE AND FRANKFURT SAUSAGE STAIN TO DARK PURPLE OR BLACK. IT DOESN’T HAPENS WITH JAM.

CONCLUSION: IODINE SOLUTION IS AN INDICATOR OF STARCH PRESENCE. POTATOE AND FRANKFURT SAUSAGE CONTAIN STARCH.

QUESTIONS

Which is the origin of the starch that you can see in the leaf?  Photosyntesis. 
Explain the significance of boiling the leaf in water? Interrupt the photosyntesis.

Explain the significance of boiling the leaf in ethanol? Extract the clorophyll. 
Explain the significane of rinsing the leaf in water? To eliminate any remains of colorophyll.