2. 1. Differentiate fats from oils.
2. Write an equation showing the
saponification of fats and oils with NaOH.
3. Draw the complete structures, showing all
bonds , for stearic acid and sodium stearate.
4. Draw structures of some syndets.

3. 1. Fats Oils
Tend to be solid or Tend to be liquid at
semi-solid at room room temperature
temperature
Usually come from Usually come from
animal sources plant sources
More saturated Less saturated

4. 2.

5. 3. Structure of stearic acid

6. Structure of sodium stearate

7. 4. Structure of some syndets

8.  To observe the preparation of soap.
 To compare syndets and prepared soap.

10.  Observation:
 When we mixed the lard & the NaOH in 35ml of 1:1
ethanol-water. The lard was insoluble in the mixture.
 When heated for 2 minutes the lard dissolved
 When heated for 5 minutes the solution became
viscous
 We stopped heating when we reached 18 minutes the
solution became very thick. (homogeneous mixture)
 After mixing a salt solution with the soap mixture the
soap from a homogeneous mixture it became little
pieces.

11. Mixed lard and NaOH solution 2 minutes 5 minutes
18 minutes

12. SOAP USED:
SYNDET LIQUID SOAP
WINGS SURF

13. Oil
Prepared: Syndet: Liquid: Distilled
water:
Miscible Miscible Immiscible Immiscible
Oil is Oil is Oil is not Oil is not
emulsified emulsified emulsified emulsified
Tap Water:
Prepared: Syndet: Liquid: Distilled
water:
No No No No
precipitate precipitate precipitate precipitate

15.  Soaps are soluble both in water and oil.
 The carboxylate end of the long-chain molecule is ionic
and therefore hydrophilic, or attracted to water.
 The long hydrocarbon portion of the molecule, however
is non-polar and hydrophobic, or water avoiding, and
therefore more soluble in oils.
 Since the liquid soap wasn’t soluble in oil. We can
conclude that it isn’t effective in removing oils from the
dishes.
 There was no precipitate formed when we placed the
soap in the tap water. This indicates that the tap water
doesn’t contain soluble sodium carboxylates .

17. CaCl2
Prepared: Syndet: Liquid:
No precipitate No precipitate No precipitate
formed formed formed
FeCl2
Prepared: Syndet: Liquid:
No precipitate Precipitate formed Precipitate formed
formed
MgCl3
Prepared: Syndet: Liquid:
precipitate formed No precipitate No precipitate
formed formed

19.  Soaps have some drawbacks
 In hard water, w/c contains Ca2+, Mg2+, Fe3+,
SO42-, and HCO3-, soluble sodium
carboxylates are converted into insoluble
metal salts (precipitate), leaving the familiar
ring of scum around bathtubs and the gray
tinge on white clothes.

20. Litmus paper test:
Prepared: Syndet:
Blue Blue
Phenolphthalein solution:
Prepared: Syndet:
Colorless to Pink Colorless to Pink

22. Litmus Paper Test:
 Since the color of the paper is blue this means
that the soaps are basic.
 Soap is made from sodium hydroxide and fats.
 The presence of sodium hydroxide makes it basic
Phenolphthalein test:
Phenolphthalein turns pink when the solution is basic
With this it is proven that the prepared soap and the
syndet are both basic which is one of the qualities of
a soap.

23. 1. Explain why you poured the hydrolyzed fat
mixture into a concentrated solution to
precipitate the soap.
2. Why is the hydrolysis of a fat called
saponification.
3. Describe the cleansing action of soap.
4. Assuming a soap to be pure sodium stearate,
give an equation.
1. That shows why its solutions are alkaline
2. For its reactions with Mg+2 in hard water
3. For its reaction with hydrochloric acid

24. 1.Because in mixing the NaOH solution to the
lard both soap and glycerol is produced.
GLYCEROL- interferes with testing so we need
to take the glycerol out to take it out we add
the salt solution which has a salting out
effect thereby removing glycerol.
Additionally, we wash the soap with cold
water to remove the remaining glycerol and
salt.

25. 2. The hydrolysis of fat is called saponification
after the Latin word sapo, “soap”. This
reaction then results to the formation of
soap. Soap is a mixture of carboxylate salts
of fatty acids derived from the fatty acids of
the triacylglycerols contained in the fat or
oil.

26. 3. The cleansing action of both soaps and detergents
results from their ability to emulsify or disperse water-
insoluble materials (dirt, oil, grease, etc.) and hold
them in suspension in water. This ability comes from
the molecular structure of soaps and detergents.
When a soap or detergent is added to water that
contains oil or other water-insoluble materials, the
soap or detergent molecules surround the oil droplets.
The oil or grease is “dissolved” in the alkyl groups of
the soap molecules while the ionic end allows the
micelle to dissolve in water. As a result, the oil
droplets are dispersed throughout the water (this is
referred to as emulsification ) and can be rinsed away

27. a.CH3(CH2)16COONa + HCl CH3(CH2)16COOH +NaCl
b.
c.

28.  Soaps are prepared through the process of
saponification. Soaps are basic, soluble in
both water and oil, but creates precipitate in
hard water (contains Ca2+, Mg2+, Fe3+, SO42-,
and HCO3-, soluble sodium carboxylates ).