L8. SAPONIFICATION

OBJECTIVES:
1) Understand saponification reaction
2) Produce soap

MATERIAL:

• 600mL beaker
• Glass Rod
• Goggles
• Gloves
• Clock Glass
• Spatula
• Bunsen Burner
• NaOH
• Water
• Oil
• Essences

PROCEDURES:

We do this experiment with 3 different measures:

Big measures: 

·         In first place take a Erlenmeyer (250ml)

·         We need to weight the necessary NaOH and water

·         When we have the weight we need to remove with a riding rod

·         Then we put the dissolution inside the Erlenmeyer

·         And we put inside the Erlenmeyer 500ml of oil

·         And we removed again

·         And finally we add the essence ( its not necessary)

·         And we put the soap in a suplement

Normal measures

·         In first place we take a beaker

·         In second place we need to do the dissolution of NaOH and water

o   First we take a wach glass and then we go to the electronic balance

o   We measuring 50g of NaOH

o   In second place we put 80ml of distillated water and the 50g of NaOH inside the beaker.

o   In third place we remove and when the dissolution are ready we also take 50ml of the dissolution

·         We take another beaker with the 50ml of the solutions and then we put inside the solution 50ml of oil

·         And we need to remove again

·         When we see the differents capes the soap are ready

·         We put the soap inside the supplement

·         We need to wait 2 or 3 days

Small measures:

·         In first place we take a test rack tube with 2 test tub

·         We go to the electronic balance.

·         We take a wach glass and we put the wach glass in the electronic balance

·         Dissolution with NaOH and water:

o    Very carfully we put 20g of  caustic sosa in the whach glass

o   After we put 80ml of distillated and 20g of sosa caustic in a beaker of 250ml and we removing the solution carfully and slowly

o   When the beaker are hot and the solution are okey

·         We take the pipet and we measured 2ml of this solution (NaOH+Water)

·         And we put this 2ml inside the two test tube

·         And  we put 2ml of oil

·         And we need to remove again

·         And finally we take a beaker and we put the two test tube inside the beaker.

·          And we put the beaker in the Bunsen burner (Water Bath)

RESULTS:

We made soap. 

QUESTIONS:

• What is soap? Solid or liquid substance that, mixed with water, serves for washing. It is obtained from the combination of an alkali with the acids of the oil or another fatty body.

• What reaction has been made?

FATTY ACIDS + ALKALINE SOLUTION = SOAP + GLYCERIN

• What layers have been produced? the soap and the glycerin

L7.LIPIDS PROPERTIES

OBJECTIVES:
1) Test the solubility of lipids.
2) Identify lipids in liquids compounds.
3) Understand what are an emulsion and the effect of detergents.

MATERIAL:

• test tubes

• 250mL beaker

• Water

• Test tube rack

• Cellulose paper

• Dropper

• Scissors

• Glass rod

• Oil

• Soap (detergent)

• ether

• ethanol

• sudan III

• MILK with different fat content: full-cream, skimmed milk and soymilk.

PROCEDURES:

SOLUBILITY OF SOME LIPIDS

1. Clean and dry three test tubes. Label as W (water), ethanol (E) and PE (ether).
2. Add 3 drops of oleic acid to 3 small test tubes.
3. Add 1mL of water in in the first test tube (W)
4. Add 1mL of ethanol in the second test tube (E)
5. Add 1mL of ether in the third test tube (PE)
6. Shake carefully each test tube

LIPIDS IDENTIFICATION:

TRANSLUCENT MARK

7. Cut two piece of cellulose paper.
8. Put 1 drop of water in the first squared piece. 
9. Put 1 drop of oil in the second squared piece. 

SUDAN III DYE

10. In first place take the W test tube of the first experiment and add 2 drops of Sudan III.
11. After  took another 4 test tube( with different fat content)

o   In first test tube one type of milk full-cream

o   In the second tube another type of milk skimmed

o   In the third tube another type of milk soya milk

o   In the last test tube we put soda (S) 

o   And finally add 2 drops of Sudan III in each of 4 test tube and observe the results.

   

    EMULSION AND EFFECT OF DETERGENT

    In first place we need to take a 250ml beaker and put 100ml of water. 

    Add 1ml of olive oil. With a glass rod stir the mixture vigorously and let it stand for a few minutes.

    Observe and make note of what is happening.

    Finally we added 2 drops of soap and stir the mixture again. Let it stand for a few minutes and notice the differences between both mixtures.

RESULTS:

WATER+OIL-> NO SOLUBLE

ETER+OIL   -> SOLUBLE

PE+ OIL-> SOLUBLE

SKIMMED MILK: The solution stain soft orange

Semi-skimmed milk: The solution stain medium orange

Soymilk: It doesn’t change the colour.

WATER AND OIL FORM A TEMPORARY EMULSION

    WATER , SOAP AND OIL FORM A PERMANENT EMULSION

QUESTIONS:

    From your observation, which compounds can dissolve lipids?   As we have obvserved in the experiment, ethanol can dissolve oleic acid

    Do the oil and water mix? What can you conclude about the polarity of the oil if you know that water is polar?   Water and oil can't mix together because water can't dissolve lipids. Oil is a non-polar compound.
Why is liquid the olive oil lat room temperature?   Because it's an insaturated acid and has a low melting point.
Why does a lipid leave a translucent spot on paper?   Beacause it's a fatty acid.
Which type of milk contains more lipids? Why?   Full-cream milk contains more lipids than the others because is fattier.Did the oil and water mix when you added the soap?   Yes

L6. STARCH

OBJECTIVES:
check whether the following substances carried starch


MATERIAL:

• test tubes

• ethanol

• leaf

• H2O

• frankfurt

• jam

• potatoe

• pipette

PROCEDURES:

1. Boil a leaf in water for two minutes.

1. Put the leaf in a test-tube with ethyl alcohol and boil it again for ten minutes.

1. Rinse the leaf with water.

1. Dye the leaf with iodine

 - FRANKFURT, POTATO, JAM

1. Cut them in two halves.

1. Dye them with iodine and put every half in a glass watch.

RESULTS:

it have starch in all ingredients

QUESTIONS:

• Which is the origin of the starch that you can see in the leaf?

• Explain the significance of boiling the leaf in the water?

• Explain the significance of boiling the leaf in ethanol?

• Explain the significance os rising the leaf in water?

L5. CARBOHYDRATES

OBJECTIVES:


1. Identify different sugars
2. Understantand the relation between structures and some propeties. 

MATERIAL:

• test tubes
• glucose
• maltose
• sacarose
• lactosa
• starch
• beaker
• bunsen burner
• pipette
• spatula
• lugol
• water destilled
• test-tube rake
• wire gauze

PROCEDURES:

LUGOL	FEHLING
5mL H2O IN A TEST TUBE	2mL H2O
ADD SACCHARIDE	2mL FEHLING A
OBSERVE	2mL FEHLING B
2 DROPS OF LUGOL	TEST TUBE IN A BOLING WATER BATH

RESULTS:

	GLUCOSE	MALTOSE	SUCROSE	LACTOSE	STARCH
SWEET	YES	YES	YES	YES	NO
SOLUBILITY	YES	YES	YES	YES	NO
LUGOL	NEGATIVE	NEGATIVE	NEGATIVE	NEGATIVE	POSITIVE
FEHLING	POSITIVE	POSITIVE	POSITIVE	POSITIVE	NEGATIVE
MONO/DI/POLI	MONO	DI	DI	DI	POLI

L4.PH

OBJECTIVES:
1. Knowing view the pH
2. Measure different acideces

MATERIAL:

• Distilled Water 

• Lemon 

• Test tubs 

• ph measure

PROCEDURES:

We cut the lemon in half. We squeeze the two pieces to get juice.Take the pipette. When we have the tubes with all quantities mixed, add the paper measuring the pH to see which number has each mixture. 

RESULTS:

Test tubs	H2O (mL)	LEMON (mL)	PH
1	5	1	3
2	4	2	3
3	3	3	3
4	0	6	3

QUESTIONS:
1. Which is the dependent variable? The pH
2. Which is the independent variable? The lemon
3. Which is the control?

4. Which pH do you think are in blood? And gastric juice? The blood problably is 7 pH because is neutral, and gastric juice is 1 because we have all the acid here.

L3. OSMOSIS

OBJECTIVES:
1. Know about the osmosis phenomena
2. Understand the process of osmosis in plasmatic membranes

MATERIAL:

• Egg

• Potato 

• NaCl

• Distilled water

• Acetic Acid (Vinegar)

• Spatula 

• 600mL Beaker

• 3 Watch glass

• Knife

PROCEDURES:

Egg:

1. Take a 600mL beaker and put inside the egg.

2. Cover the egg with vinegar and make note of what’s happening. 
Once the egg’s shell is removed and the egg is rinsed dry and clean, measure and weigh the egg. Record the dimensions of each egg in a table.

Potato:

1. Lay out three watch glass.

2. Slice the potato in three parts lengthwise.

3. Place each slice onto a watch glass and make a hole in the middle of each slice. NOTE: the hole does not have to cross the slice!

4. In the first slice hole, don’t put anything. The second fill it with NaCl and the third with distilled water.

5. Left this preparation 30 minutes and make note of what is happening




RESULTS:

QUESTIONS:

Egg experiment:

1. What is happening when the shells are soaking of acetic acid?

2. Write the results of de dimensions and weigh of the egg before and after immersing it in distilled water. Write and draw a simple diagram of the water direction.

Potato experiment:

3. Explain the results of this experiment.

4. Why have we left the first slice without any treatment (salt or distilled water)?


5. Which are the dependent and independent variables? 

L2. MINERAL SALTS IN ORGANISMS

OBJECTIVES:


1. Identify mineral salts in organisms
2. Understand the function of inorganic biomolecules in skeletal structures of organisms

MATERIAL:

• Acetic Acid
• Chicken bones
• Mollusks
• Baker 

PROCEDURES:

Chicken bones

1. Carefully clean and cut ad much of the meat away from the chicken thin bone as possible.
2. Examine the flexibility of the bone by trying to bend it with your fingers.
3. Take a beaker and make and acid acetic solution or add vinegar.
4. Take the chicken bones and drop them in the acid acetic solution (vinegar) that you have made.
5. tLeave it 24 hours and see what happens to the bone.
6. Write the results in your lab worksheet.

Mollusks shells

1. Take another beaker and make the same acid acetic solution.
2. Put inside some shells and make note of what is happening.
3. Write the observations in your lab worksheet.

RESULTS:

Chicken bones

The bones are more flexibility because of the lack of calcium.

Mollusks shells

The mollusks have desintegrated

QUESTIONS:

1. Write the reaction that takes place when the acid acetic reacts with the calcium carbonate. Calcium carbonate react with acetic acid: CaCO₃ + 2CH₃COOH → Ca(CH₃COO)₂ + H₂O + CO₂ 
2.  What is happening when the shells are soaking of acetic acid? What are the bubbles that you can see? when the shells are soaking the acetic acid it make bubbles. This bubbles are CO2.
3. What is happening to the bone after some days of soaking it in acetic acid? Why is the bone flexible now?  the bones are more flexible when dissolved the acetic acid because the bone is mainly made of calcium salts that are responsible for the hardness of the bones. When subjected to the action of vinegar (acetic acid), a chemical and much bone calcium vinegar reaction will go towards forming another substance called calcium acetate, losing in this way hardness, and becomes flexible.
4. So, what is the function of the calcium carbonate in the skeletal structures? the funcion is give rigidity on the bones
5. Increases in carbon dioxide to the atmosphere from the burning fossil fuels and deforestation threaten to change the chemistry of the seas. Evidence suggests that this increase in atmospheric carbon dioxide is lowering the pH of the oceans in a process called ocean acidification. How can acidification affects corals reefs? Cuando el CO2 de la atmósfera se disuelve en el agua, el pH baja ligeramente y se producen cambios químicos de los carbonatos. Esto a su vez hace más difícil formar sus conchas y esqueletos a una serie de animales marinos