1. CARBON COMPOUNDS
FATS AND
NATURAL RUBBER

2. terms Saturated fat Unsaturated fat
Fat molecule that has no carbon –carbon double bonds
Fat molecule that has at least ONE carbon –carbon double bonds

3. terms Oil Fat Liquid at room temperature and found in plants
Solid at room temperature and found in animals

4. terms Glycerol Fatty acids
An alcohol that has 3 hydroxyl group in 1 molecule
Carboxylic acid that has a long chain carbon, about 10 to 20 carbon atoms and has only one carboxyl group

5. terms Examples of oils Coconut oil, corn oil Examples of fats
Meat, butter, cheese

6. terms Examples of saturated fats Examples of unsaturated fats
Meat, butter, cheese
Soybeans, peanuts, sunflower seeds, maize

7. terms cholesterol Hydrogenation
White, fatty substance that make blood vessels become hard and narrow
Addition of hydrogens to the double bonds between 2 carbon atoms

8. OILS AND FATS a) State 2 similarities between fats and oils?
Both are esters
Both occur naturally in living tissues of organisms

9. b) Fill in the table below to list
differences between oils and fats
Oils
Fats
sources
Plants and animals
Animals
Physical state
liquid
solid
Melting point
Lower than 20 oC
Higher than 20 o C

10. c) Fill in the table below to list differences
between saturated and unsaturated fats
Unsaturated fats ( C=C)
Saturated fats
(C-C)
Proportion of molecules between saturated and unsaturated fats
More unsaturated molecules than saturated molecules
More saturated molecules than unsaturated molecules

11. c) Fill in the table below to list differences
between saturated and unsaturated fats
Unsaturated fats ( C=C)
Saturated fats
(C-C
b) Physical state at room temp
Mostly liquids
Mostly solids

12. c) Fill in the table below to list differences
between saturated and unsaturated fats
Unsaturated fats ( C=C)
Saturated fats
(C-C)
c) Melting point
Lower melting point
Higher melting point

13. c) Fill in the table below to list differences
between saturated and unsaturated fats
Unsaturated fats ( C=C)
Saturated fats
(C-C)
d) sources
Plants and vegetables
Animals

14. d) Why do unsaturated fats turn bad or spoil easily?
They contain carbon-carbon double bond that can easily reacts in the air.

15. e) Explain how unsaturated fats can be changed to saturated fats?
Through catalytic hydrogenation
Where carbon-carbon double bond absorbs one mole hydrogen
The process is carried out by bubbling hydrogen gas through hot liquid oil in the presence of fine particles of nickel catalyst at temp of 200 o C and pressure 4 atm

16. FORMATION OF FATS OR OILS
 Three molecules of fatty acids combine with one molecule of glycerol to form a fat molecule and water + 
Carboxylic
acids
Alcohol
Fats or oil
water
3 molecules Fatty acid
1 molecule
Glycerol or 1,2,3- propanetriol
Has a very long chain carbon, (about atoms)
Examples, palmitic acids, stearic acids, linoleic acids

17. a) From diagram above, what is glycerol?Draw its molecular formula
Glycerol is an alcohol with three hydroxyl group in one molecule of glycerol

18. b) From diagram above, what is the difference between a fat molecule and a fatty acid molecule?
A fat molecule is formed when long-chained carboxylic acid reacts with alcohol with three OH-groups (glycerol)
A fatty acid molecule is carboxylic acid molecule that has a long chain carbon atom ( about atoms)

19. c) Hexanoic acid and pentanol react together to form a product
c) Hexanoic acid and pentanol react together to form a product. Name the product formed and state its homologous series
Name of product: pentyl hexanoate
Homologous series : ester

20. Can hexanoic acid and pentanol react together to form Fat or Oil
Can hexanoic acid and pentanol react together to form Fat or Oil? Explain your answer
No, because hexanoic acid is a short chain carboxylic acid with carbon atoms only 6 atoms and pentanol is not a glycerol

21. Can decanoic acid and glycerol react together to form Fat or Oil
Can decanoic acid and glycerol react together to form Fat or Oil? Explain your answer
Yes, because decanoic acid is a long chain carboxylic acid with carbon atom is 10 and reacts with glycerol

22. NATURAL RUBBER a) List examples of natural polymers and their monomers1
Starch
glucose 2
Cellulose 3
Protein
Amino acid 4
Rubber
Isoprene or 2- methylbut-1,3-diene

23. Complete the structural formula of natural rubber in the diagram below

24. Or draw the structural formula of natural rubber in a simpler form

25. *** draw structure of its monomer!
2-METHYLBUT-1,3-DIENE

26. b) State the properties of natural rubber
White ……SOLID……… at room temperature
Elasticity that ………DECREASE …… overtime
Soft
Sensitive to …………HEAT..

27. State 3 uses of natural rubber
In the making of tyres, footwear, rubber threads, rubber foam, conveyor belts and bitumen roads
Buildings built on rubber blocks or rubber bearings to help absorb vibration
Making of gloves, tubes and hoses

28. Describe the coagulation of latex
Latex is a …………COLLOID…………
It consists of ……RUBBER PARTICLES particles dispersed in ……WATER…
Each rubber particle is made-up many long-chain ………RUBBER………..molecules enclosed by a ………PROTEIN..-like membrane which is ……NEGATIVELY-charged

29. Describe the coagulation of latex

30. Process 1
The repulsion between the ……NEGATIVELY …..charged particles prevent the ……RUBBER particles from coming close to each OTHER THEREFORE LATEX COULD NOT COAGULATE

31. Process 2
When an ACID is added to latex, OR when latex is exposed to AIR , the BACTERIA ..from the air enters the latex and produce LACTIC acid that form HYDROGEN …ions. This HYDROGEN ….ions neutralize the NEGATIVE charges on the protein membrane.

32. Process 3
The rubber PARTICLES can now come close together. This enable them to COLLIDE .with one another resulting in the BREAKAGE of the protein membranes.

33. Process 4
The rubber molecules combine with one another and entangle and thus causing the latex to coagulate
 Draw diagram .

34. iv) Describe how to prevent the coagulation of latex
By adding AMMONIA ….solution, that contains …HYDROXIDE ……….ions which …NEUTRALIZE ………. the acid produced by the bacteria . Therefore rubber particles remain …NEGATIVELY…… charged and the coagulation is PREVENTED

35. VULCANISED RUBBER
a) What is meant by vulcanization of rubber?
ADDITION OF SULPHUR TO RUBBER AT 140 OC AND HIGH PRESSURE IN THE PRESENCE OF ZINC OXIDE AS THE CATALYST

36. b) In industry, how does the vulcanization of rubber is carried out?
By heating latex with SULPHUR or a solution of sulphur monochloride in methylbenzene as solvent

37. c) Describe how sulphur atoms change the properties of rubber
In vulcanization , sulphur ….atoms form cross-link …between rubber molecules
These cross – LINK prevent rubber MOLECULES from sliding too much when STRETCHED
The rubber molecules return to their ORIGINAL ….. position after being stretched.

38. d) Draw cross-linkage of sulphur

39. e) Compare and contrast the properties of vulcanized and unvulcanised rubber
Similarities
Both are ELASTIC
Both are HEAT AND ELECTRICAL INSULATORS

40. Differences Vulcanised Differences Unvulcanis ed rubber More elastic
Elasticity
LESS elastic
Harder
Hardness
SOFTER
More tensile strength
Tensile strength
LESS tensile strength

41. Differences Vulcanised Differences Unvulcanis ed rubber
More resistance to heat
Resistance to heat
LESS resistance to heat
LESS SOLUBLE
Effect of organic solvents
MORE SOLUBLE

42. f) State one advantage of natural rubber over synthetic rubber
Only natural rubber can take the tremendous STRESS, STRENGH AND HEAT ………produced during landing and taking off of an aero plane