NCERT CHAPTER - 4 SCIENCE CARBON AND ITS COMPOUNDS

1. Chapter – 4
CARBON
AND ITS COMPOUNDS
1
10th standard
science

2. 2
Wel Come
Presenting:
SHASHIKUMAR B.S.
GHS, ELEKYATHANAHALLI
NELAMANGALA TQ,
BENGALURURU RURAL DIST.

3. • Covalent bond
• Electron dot structure
• Catenation
• Isomerism
• Hydrocarbons and their classification
• Functional groups
• Homologous series
• Esterification
• Soaps and detergents
3
LEARNING POINTS

4. Position of carbon in periodic table
• The symbol of carbon – C
• Atomic number Z= 6
• Group – 14
• Period – 2
• Carbon is a Non - metal
4

5. 5
K – 2/2e- completely filled
L - 4/8e- partially filled
Tetravalency

6. 6
Carbon atom sharing its valence
electrons with surrounding other
carbon atoms and forming a
covalent bond
Covalent bond
Covalent bond: The bond formed by
sharing of electrons between the
atoms is called covalent bond

7. Covalent bond:
Ex: Bonding in methane (CH4)
Valence electron in Hydrogen atom is – 1
Valence electrons in Carbon atom is - 4
Bond formed between one carbon atom with 4
hydrogen atoms
7

8. Electron dot structures
Oxygen molecule‍- O2
Ammonia- NH3
Carbon dioxide - CO2
Sulphur dioxide - SO2
Methane -‍CH4
Ethane - ‍C2H6
8

9. Catenation:
carbon form covalent bond with surrounding
other carbon atoms, and forms chain structures,
this unique property of carbon is called
catenation
Types of chain structures:
Straight chain
Branched chain
and
Closed / Ring chain
9

10. Isomerism
The carbon compounds having identical
molecular formula and different
structures are called isomers and the
phenomenon is called isomerism
10

11. Isomers
11
Ex: n-Butane
mol. Formula : C4H10
Iso-Butane
mol. Formula: C4H10

12. Tetra valency
Catenation
Isomerism
Unique properties of carbon
12

13. Hydrocarbons
• The Compounds which are formed
only by hydrogen and carbon are
called hydrocarbons
• The simplest hydrocarbon is
Methane, its mol. formula CH4
13

14. Classification of hydrocarbons
Alkane‍ C – C CnH2n+2
Alkene‍ C = C CnH2n
Alkyne C ≡ C CnH2n-2
14

15. Alkanes
15

16. Alkenes
16

17. Alkynes
17

18. Cyclic Alkanes
In addition to straight and
branched carbon chains, some
compounds have carbon atoms
arranged in the form of a ring
18

19. Cyclic Alkanes
19

20. Saturated hydrocarbons
Methane
Iso Butane
propane
Cyclo Hexane
20
Ethane

21. Saturated hydrocarbons
The Valencies of all the carbon
atoms in a compound is fulfilled
by only single bonds (C – C) are
called Saturated hydrocarbons.
Ex: alkanes and cyclic alkanes
21

22. Unsaturated hydrocarbons
Benzene
22
Ethene Ethyne

23. Unsaturated hydrocarbons
The Valencies of carbon atoms in a
compound is fulfilled by double
(C = C) or triple (C ≡ C) bond along
with single bonds are called
unsaturated hydrocarbons.
Ex: alkenes, alkynes and benzene
23

24. Functional Groups
24
Carbon is a very friendly element,
it can easily make friendship with
hydrogen atom. Sometimes it can
also make friendship with other
elements like Cl, Br, and other
molecules like OH, CHO, C=O,
COOH and gets specific
properties,
In hydrocarbon chain hydrogen
atom or atoms replaced by other
atom or molecules and they are
responsible for special properties
of hydrocarbon compounds.
These atoms groups are called
functional groups

25. Functional Groups
25
Cl – chloro
Br – bromo
OH – alcohol
CHO – aldehyde
C=O – ketone
COOH – carboxylic acid

26. 26

27. 27
Naming of Carbon compounds with
functional groups

28. 28
Naming of Carbon compounds with
functional groups

29. Homologous series
A Homologous series is a group
of carbon compounds having
similar structures, similar
chemical properties and
whose successive members differ
by a – CH2 group.
29

30. Homologous series
Ex: CH3OH C2H5OH C3H7OH C4H9OH
CH2 CH2 CH2
Alcohol series
30

31. Chemical properties of Carbon
compounds
Combustion:
It is a type of chemical reaction
(oxidation),
carbon on heating burns to produce heat
and light as energy
* Heat and light are not always the products of
combustion, some times combustion produces
some new products.
31

32. Types of combustion
If the air is available
Sufficient amount, fuel
burns completely,
it is called complete
combustion.
If the availability of the
air is not sufficient
amount, fuel burns
partially, it is called
incomplete combustion.
32

33. Types of combustion
Saturated hydrocarbons will
generally give a clean
flame,
while unsaturated carbon
compounds will give a
yellow flame with lots of
black smoke.
33

34. Oxidation:
Carbon compounds like alcohols are
oxidised to produce carboxylic acids on
heating, with oxidising agents like alkaline
Potassium permanganate – KMnO4 or acidic
potassium dichromate - K2Cr2O7.
34
Ethanol Ethanoic acid

35. Addition reaction
Unsaturated hydrocarbons undergo
addition reaction with hydrogen, in
presence of nickel or palladium as catalyst
to form saturated hydrocarbons.
Eg:- Ni or Pd catalyst
C2H4 + H2 C2H6
35

36. Hydrogenation
The addition of
hydrogen to unsaturated
hydrocarbons to form
saturated hydrocarbons
is called hydrogenation.
Uses: Hydrogenation is
used to convert
unsaturated oils and fats
to saturated oils and fats.
36

37. Hydrogenation of oils
Ni
37

38. Substitution reactions
Saturated hydrocarbons undergo
substitution reaction with
halogens to form substitution
products.
Eg :- Methane undergoes substitution reaction with
chlorine in the presence of sunlight to form
substitution products.
CH4 + Cl2 CH3Cl + HCl
(in the presence of sunlight)
38

39. Some important carbon compounds
Ethanol: alcohol/ ethyl alcohol, C2H5OH/ CH3CH2OH
• Ethanol is a colorless liquid with a pleasant smell
• It is completely soluble in water
Ethanol reacts with sodium to form sodium ethoxide
and hydrogen
2Na + 2CH3CH2OH  2CH3CH2O Na + H2
(Sodium ethoxide)
Uses :-
i) Ethanol is used for making alcoholic drinks.
ii) It is used as a solvent.
iii) It is used for making medicines like tincture iodine, cough
syrups, tonics , etc.
39

40. Ethanoic acid: Acetic acid (CH3COOH)
Properties :-
• Ethanoic acid is a colourless liquid with a
pungent smell and sour taste.
• It is soluble in water.
• A solution of 5% to 8% ethanoic acid in water is
called Vinegar.
40

41. Esterification
Ethanoic acid reacts with ethanol to
form the ester ethyl ethanoate
in presence of conc. H2SO4.
conc.H2SO4
CH3COOH + C2H5OH CH3COOC2H5 + H2O
The reaction between carboxylic acid and alcohol
to form an ester is called esterification
41

42. Saponification
When an ester reacts with
sodium hydroxide solution,
the sodium salt of the
carboxylic acid and the
parent alcohol are formed.
This reaction is called
saponification.
42

43. Soaps
43
Soaps are the sodium or
potassium salts of long chain
fatty acids
Ex: sodium stearate,
sodium oleate,
sodium palmitate

44. Structure of a soap molecule
44
A soap molecule has two parts.
A long hydrocarbon part, which is
hydrophobic in nature and soluble in oil,
grease.
A short ionic part which is hydrophilic in
nature (water attracting) and insoluble in
oil and grease.
COO - Na +

45. Cleansing action of soap
45
When soap is dissolved in water it forms
spherical structures called micelles.
• In each micelle the soap molecules are
arranged radially.
• such that the HC part is towards the
center and the ionic part is towards the
outside.
• The HC part dissolves the dirt, oil and
grease and forms an emulsion at the
center of the micelles
• which can be washed away by water.

46. Micelles
46
Oil drop
COO
_

47. Detergents
Soapless soaps are called Detergents.
Detergents are long chain sodium
salts of sulphonic acids
47

48. Differences
48
Soaps Detergents
• Soaps are sodium salts
of fatty acids.
• Detergents are sodium
salts of sulphonic acids.
•Soaps clean well in soft
water but do not clean
well in hard water.
• Detergents clean well with
both hard and soft water.
• Soaps do not clean as
well as detergents.
• Detergents clean better
than soaps.
• Soaps are biodegradable
and do not cause
pollution.
• Some detergents are
non biodegradable
and cause pollution.

49. Probable Questions:
• Name the unique properties of Carbon.
• Explain the covalent bond in methane
molecule.
• Write the electron dot structures of O2, CO2,
NH3 , SO2 , CH4 , C2H6.
• Explain the covalent bond formation in
Hydrogen.
• What is isomerism? Write the possible
isomers for pentane(C5H12).
• Write the three compounds of homologous
series of molecular formula C2H5COOH.
49

50. Probable Questions:
• What happens when methane and chlorine
mixture is exposed to sun light? What is the
reaction taking place?
• Write the balanced chemical equation of alcohol
reacts with sodium. What does this reaction
infer?
• What is esterification? What are the uses of
esters?
• Alcohol is not used as a soap or detergent. Why?
• Briefly explain the cleansing action of soap.
• Practice the naming of functional groups with
carbon compounds 50

51. 51
Thank you
Presenting:
SHASHIKUMAR B.S.
GHS, ELEKYATHANAHALLI
NELAMANGALA TQ,
BENGALURURU RURAL DIST.