Chapter 2 Carbon Compounds

1. CHAPTER 2
Carbon Compounds

2. 2.1 Carbon Compounds
• Carbon compounds:
Compounds that contain carbon as one of
their constituent elements

3. Carbon compounds
Organic compounds Inorganic compounds
• Carbon-containing
compounds that can
be obtained from
living things
• Except oxides of
carbon, carbonates,
cyanides and metallic
carbides
• Examples:
 Non-carbon-containing
compounds that can be
obtained from non-living
things
 Include oxides of carbon,
carbonates, cyanides and
metallic carbides
 Examples:

4. Hydrocarbon
• Hydrocarbon:
Organic compounds which contains carbon and
hydrogen only
• Examples:
Petroleum, coal, natural gas, rubber tree
• Non-hydrocarbon:
Organic compounds containing carbon, hydrogen
together with a few other elements
• Examples:
Sugar

5. Organic compounds
Hydrocarbons
C and H
Saturated
hydrocarbon
Unsaturated
hydrocarbon
Non-hydrocarbons
C, H and O, N, P, S, F,
Cl, Br and I
 Contain only
single bonds
 Contain at least
one multiple
bonds
C C
C C C C

6. Combustion products of organic compounds
• When an organic compound burnt in excess
oxygen, the main product are carbon dioxide,
CO2 and water, H2O
C6H12O6 + 6O2 → 6CO2 + 6H2O
glucose

7. Alkanes, alkenes, alcohols,
carboxylic acids and esters

8. 1. Molecular formula
• Meaning
The formula that shows the actual numbers
and types of atoms present in a molecule.
Molecular formula Explanation
Propane, C3H8 Contains 3 carbon atoms and 8
hydrogen atoms
Pentane, C5H12 Contains 5 carbon atoms and 12
hydrogen atoms

9. 2. Structural formula
• Meaning
The formula that shows how the atoms in a
molecule are bonded together and by what
types of bonds
Molecular formula Structural formula
Propane, C3H8
C C C
HHH
H
HHH
H

10. 3. Naming of carbon compound (IUPAC)
• Guideline to naming the carbon compound:
Have 2 components
Root Ending
Show the number
of carbon atoms in
the molecules
Show the family
of the compound

11. a) stem/root
Number of
carbon
atom
1 2 3 4 5 6 7 8 9 10
Stem Meth Eth Prop But Pent Hex Hept Oct Non Dec

12. b) suffix/ending
• Ending; different followed by the
homologous series
Homologous series Ending
Alkane ……ane
Alkene ……ene
Alcohol ……ol
Carboxylic acid ……oic acid
Ester ……yl ……..oate

13. B. ALKANES
Physical properties of alkanes
• Alkanes are covalent compounds which
consist of simple molecules
• Molecules are held together by weak
intermolecular force

14. Physical
properties of
alkanes
Electrical
conductivity
• Cannot conduct
electricity
• Because there
are no free
moving ions
Density
• Less dense than
water
Solubility
• Dissolve in
organic solvents
• Insoluble in
water
Melting and
boiling point
• Low melting &
boiling point
Physical state at
room
temperature
• C1 to C4 are gases
• C5 to C17 are
liquid
• C18 > are solid

15. Explain the effect of the increase in number of
carbon atoms in alkane molecules
Size of molecule increase
Melting point & boiling point increase
• The higher the number of carbon atoms, the
higher the melting & boiling point

16. • As the number of carbon atoms increases, the
molecule become bigger
• The force of attraction between the molecules
become stronger
• More heat energy is needed to overcome the
strong force of attraction between molecules

17. Why melting and boiling point propane is higher
than ethane?
• Propane have more number of carbon atoms per
molecule than ethane
• Size of propane is bigger than ethane
• The force of attraction between propane
molecule increase
• More heat energy is needed to overcome the
force of attraction between propane molecule
• So, melting and boiling point of propane is higher
than ethane

18. Chemical properties of alkanes
Combustion
a) Complete combustion: produce CO2 + H2O
C2H6 + O2 → CO2 + H2O
b) Incomplete combustion: produce CO/C gas +
H2O
2CH4 + 3O2 → 2CO + 4H2O
CH4 + O2 → C + 2H2O

19. Halogenation
• Reactions of alkanes with halogens
• Take place readily in sunlight/ultraviolet
• Example of substitution reaction
Reaction that occurs when one
atom or a group of atoms in a
molecule is replaced by another
atom or group of atoms

20. • CH4 + Cl2 → CH3Cl + HCl
• CH3Cl + Cl2 →
• CH2Cl2 + Cl2 →
• CHCl3 + Cl2 →

21. C. ALKENES
Physical properties of alkenes are similar to
alkanes
• Molecules are held together by weak
intermolecular force

22. Physical
properties of
alkenes
Electrical
conductivity
• Cannot conduct
electricity
• Because there are
no free moving
ions
Density
• Less dense than
water
Solubility
• Dissolve in organic
solvents
• Insoluble in water
Melting and
boiling point
• Low melting &
boiling point

23. Explain the effect of the increase in number of
carbon atoms in alkene molecules
Size of molecule increase
Melting point & boiling point increase
• The higher the number of carbon atoms, the
higher the melting & boiling point

24. Why melting and boiling point butene is higher
than ethene?
• Butene have more number of carbon atoms per
molecule than ethene
• Size of butene is bigger than ethene
• The force of attraction between butene molecule
increase
• More heat energy is needed to overcome the
force of attraction between butene molecule
• So, melting and boiling point of butene is higher
than ethene

25. Chemical properties of alkenes
Combustion
(a) Complete combustion: produce CO2 + H2O
C2H4 + O2 → CO2 + 2H2O
(a) Incomplete combustion:
produce CO/C gas + H2O
C2H4 + 2O2 → 2CO + 2H2O
C2H4 + O2 → 2C + 2H2O

26. Hydrogenation
• Alkenes react with hydrogen at 180 °C at
presence of nickel/platinum (catalyst) to
produce alkanes
C2H4 + H2 C2H6
Ni, 180 °C

27. Halogenation
• No catalyst or ultraviolet is needed
• Alkenes react with halogen at room
temperature in the presence of
tetrachloromethane, CCl4
C2H4 + Cl2 → C2H4Cl2
C4H8 + Br2 → C4H8Br2
Used to test for the presence of a carbon-carbon double bond

28. Hydration
• Alkenes reacts with steam, H2O at 300 °C and
60 atm in the presence of concentrated H3PO4
(as catalyst) to produce alcohol
C2H4 + H2O C2H5OH
H3PO4
300 °C, 60 atm

29. Addition of hydrogen halides – HX
• Hydrogen halides: Hydrogen chloride, HCl or
hydrogen bromide, HBr
• Alkenes reacts with hydrogen halide, HX at
room temperature to produce haloalkane
C2H4 + HCl → C2H5Cl

30. Addition of hydroxyl group
• Alkenes react with acidified potassium
manganate(VII), KMnO4 to produce diol
compound
C2H4 + H2O + [O] → C2H4(OH)2
or
C2H4 C2H4(OH)2
KMnO4
Used to test for the presence of a carbon-carbon double bond

31. Polymerization reaction
• Small alkene molecules undergo an addition
reaction with one another at high pressure of
1000 atm and temperature 200 °C
C C
HH
HHn C C
HH
HH
n

32. Compare & contrast alkanes with alkenes
• What do alkanes and alkenes have in
common?
• How do they differ from each other?

33. Comparing chemical properties
Reactivity
Procedure:
1. Pour 2 cm3 of propane and propene into each
crucible.
2. The liquids are lighted.
3. When burning occurs, filter paper is placed
on top of the flame.
4. All the observation is recorded.

34. Observation:
Propane:
Burn in air, producing yellow sooty flame
Propene:
Burn in air, producing yellow and a very sooty flame
Conclusion:
Propene is more reactive than propane

35. Describe two chemical test to differentiate
between hexane and hexene

36. • Reaction with bromine water
Procedure:
1. Pour about [2-5 ] of hexane into a test tube.
2. Add 4-5 drops of bromine water and shake it.
3. Observe any changes and repeat with hexene.
Observation:
Hexane: Brown colour of bromine remains unchanged
Hexene: Brown colour of bromine decolourise/turn
colourless

37. • Reaction with acidified potassium manganate(VII) solution
Procedure:
1. Pour about [2-5 ] of hexane into a test tube.
2. Add 4-5 drops of acidified potassium manganate(VII)
solution and shake it.
3. Observe any changes and repeat with hexene.
Observation:
Hexane: Purple colour of KMnO4 remains unchanged
Hexene: Purple colour of KMnO4 decolourise/turn colourless

38. Determine which one is more soot between
hexane and hexene when burn in oxygen. Give
your reason.

39. Hexane, C6H14
= 6(12) x 100
[6(12)+14(1)]
= 83.72%
Hexene, C6H12
= 6(12) x 100
[6(12)+12(1)]
= 85.71%
Hexene has high percentage of carbon by mass than
hexane.
So, hexene burn with more sooty flame

40. Physical
properties of
ester
State
• Simple ester is
colourless liquid at
room condition
Solubility
• Slightly soluble in
water but readily
dissolve in organic
solvent
Density
• Low density
Boiling point
• Low boiling
point
Odour
• Sweet pleasant
smell (fruity
smell)

41. E. ALCOHOL
Industrial production of ethanol
• Two main process:
(a)From sugar and starch by fermentation
(b)From petroleum fraction by hydration

42. 1. Fermentation
C6H12O6 → 2C2H5OH + 2CO2
• From sugar & starches
• Yeast added
• Left in warm place (absence of oxygen)-
anaerobic
Temperature = 18 – 20 °C
Catalyst = yeast (zymase)
Other condition = absence of oxygen

44. 2. Hydration
C₂H₄ + H2O → C2H5OH
• From petroleum fractions
Temperature = 300 °C
Pressure = 60 atm
Catalyst = phosporic acid, H3PO4

45. Chemical properties of alcohols
Combustion
(a) Complete combustion: produce CO2 + H2O
C2H5OH + 3O2 → 2CO2 + 3H2O

46. Oxidation reaction
• React with the oxidation agent:
a) acidified potassium manganate(VII), KMnO4
(purple → colourless)
b) acidified potassium dichromate(VI), K2Cr2O7
(orange → green)
C2H5OH+ 2[O] → CH3COOH + H2O
Ethanol Ethanoic acid

48. Dehydration
• Removal of water molecule from alcohol
molecule
C2H5OH → C2H4 + H2O
• Method:
(a) Heated under reflux at 180 °C with excess
concentrated H2SO4 or
(b) Pass over a heated catalyst (porcelain chips,
porous pot, Al2O3
Ethanol Ethene

50. Uses of alcohols
As a solvent in
• Perfumes, cosmetics, toiletries
As a thinner in
• Lacquer, varnish, shellac, ink
As a cleaner for
Compact disc, video cassette recorder head
As a fuel
• Clean fuel, biofuel, gasohol

51. As a raw material in manufacture of
• Vinegar, fibre, explosive, plastic
As a raw material to make pharmaceutical
products
• Tincture, antiseptic, cough syrup, rubbing
alcohol

52. F. CARBOXYLIC ACIDS
Functional group
• Carboxyl group ( -COOH )
General formula
• CnH2n+1COOH

53. Physical
properties of
carboxylic
acids
State
• Larger molecules
(C10 above) are
wax-like solids
Solubility
• Simple molecules are
very soluble in water
• Due to water molecule
being strongly
attracted to the –
COOH group
• Solubility ↓ when
number of carbon per
molecule ↑
Colour
• Colourless
liquid
Boiling point
• High boiling
point
Odour
• Sharp/unplea
sant smell

54. Synthesised/making of ethanoic acids
Oxidation of alcohol
C2H5OH+ 2[O] → CH3COOH + H2O
• Reflux ethanol with acidified potassium
dichromate(VI) solution or acidified potassium
manganate(VII) solution
Ethanol Ethanoic acid

55. Chemical properties
Acid properties
• CH3COOH is a weak monoprotic acid
• Only one hydrogen atom can ionize in water to
produce H+ ion
CH3COOH ↔ CH3COO- + H+
• Partially dissociate in water
• Turn moist blue litmus → red
• React slowly with metals, bases and carbonates
Ethanoic acid Ethanoate ion

56. Reaction with metals
Carboxylic acid + metal → salt + H2
2CH3COOH + Zn → Zn(CH3COO)2 + H2
Ethanoic acid Zinc ethanoate

57. Reaction with bases
Carboxylic acid + bases → salt + H2O
CH3COOH + NaOH → CH3COONa + H2O
2CH3COOH + CuO → Cu(CH3COO) 2 + H2O
Ethanoic acid Sodium
ethanoate
Ethanoic acid Copper
ethanoate

58. Reaction with carbonates
Carboxylic acid + carbonates → salt + CO2 + H2O
2CH3COOH + CaCO3 → Ca(CH3COO)2 + CO2 + H2O
Ethanoic acid Calcium
ethanoate

59. Reaction with alcohols
Carboxylic acid + alcohol → ester + H2O
Catalyst: Concentrated H2SO4
CH3COOH + C4H9OH → CH3COOC4H9 + H2O
Ethanoic
acid
Buthyl ethanoateButan-1-ol

60. Uses of carboxylic acids
Ethanoic acid
• As a flavouring
• As a preservative
• Used with other chemicals to make drugs, dyes, paints,
insecticides and plastics
Methanoic acid
• Used to coagulate latex
Fatty acids (long-chain carboxylic acids)
• Used in making soaps
Benzoic acid
• Preservative in food

61. G. ESTER
Functional group
• Carboxylate group ( -COO- )
General formula
• CnH2n+1COOCmH2m+1
Naming ester

62. Physical
properties of
alcohol
State
• C1 to C11 are
liquid at room
temperature
Solubility
• Simple
alcohols are
very soluble
in water
• Because has
–OH group
Colour
• Colourless
liquid at room
temperature
Boiling point
• Low boiling
point
compare to
water
Odour
• Very sharp
smell
Highly
volatile

63. Formation of ester
Esterification reaction
• Catalyst: Concentrated H2SO4

64. Natural sources
Fruit
Pineapple – C3H7COOC2H5
Ethyl butanoate
Flower
Jasmine – CH3COOCH2C6H5
Benzyl ethanoate

65. Use of ester
• Preparation of cosmetics & perfumes
• Used as food additives (enhance the flavour &
smell of processed food)
• Production of soap & detergent