Class 10 Science — Chapter 4
Carbon and its Compounds (Complete Ultra-Detailed Revision Notes)
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SECTION 1: INTRODUCTION TO CARBON & COVALENT BONDING
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* Occurrence of Carbon:
- Carbon is a versatile element found in very small amounts but holds immense importance.
- In the Earth's crust, it is present as minerals (0.02% like carbonates, coal, petroleum).
- In the atmosphere, it is present as Carbon Dioxide gas (0.03%).
- All living structures (plants, animals, humans) are carbon-based organic matter.
* Versatility of Carbon (Atomic Number = 6):
- Electronic Configuration of Carbon is 2, 4. It has 4 valence electrons.
- To attain a stable noble gas configuration, it needs to either gain 4 electrons or lose 4
electrons.
- Why Carbon cannot form C4+ or C4- ions?
1. It cannot gain 4 electrons (C4-) because it would be difficult for 6 protons in the nucleus
to hold 10 electrons.
2. It cannot lose 4 electrons (C4+) because it requires a huge amount of energy to remove
👉
4 electrons from the atom.
Solution: Carbon shares its valence electrons with other atoms.
* 🤝 Covalent Bond (सहसंयोजक बंध):
- The chemical bond formed by the sharing of electrons between two atoms is called a
Covalent Bond.
- Examples of Single Covalent Bonds: Hydrogen molecule (H₂), Water (H₂O), Ammonia
(NH₃), Methane (CH₄).
- Example of Double Covalent Bond: Oxygen molecule (O₂), Carbon Dioxide (CO₂).
- Example of Triple Covalent Bond: Nitrogen molecule (N₂).
* Properties of Covalent Compounds:
1. Low Melting and Boiling Points: Because the intermolecular forces between the
molecules are very weak.
2. Poor Conductors of Electricity: As electrons are shared, no charged particles or free ions
are formed to conduct current.
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SECTION 2: VERSATILE NATURE OF CARBON & HYDROCARBONS
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Carbon forms millions of compounds due to two unique chemical properties:
1. Catenation (श्रख
ं ृ लन): Carbon has the unique ability to form strong covalent bonds with
other carbon atoms, giving rise to long straight chains, branched chains, or closed rings.
2. Tetravalency (चतःु संयोजकता): Since carbon has a valency of 4, it can bond with four other
carbon atoms or atoms of elements like Oxygen, Hydrogen, Nitrogen, and Sulphur.
, * HYDROCARBONS (यौगिक जो केवल कार्बन और हाइड्रोजन से बने हैं):
1. Saturated Hydrocarbons (संतप्ृ त - Alkanes): Contains only Single bonds between carbon
atoms.
- General Formula: CnH2n+2 (Examples: Methane CH₄, Ethane C₂H₆).
2. Unsaturated Hydrocarbons (असंतप्ृ त - Alkenes & Alkynes): Contains Double or Triple
bonds.
- Alkenes (Double bond): General Formula is CnH2n (Example: Ethene C₂H₄).
- Alkynes (Triple bond): General Formula is CnH2n-2 (Example: Ethyne C₂H₂).
* Allotropes of Carbon (कार्बन के विभिन्न रूप):
The same element existing in different physical forms with similar chemical properties.
1. Diamond: Three-dimensional rigid network. It is the hardest known natural substance.
Poor conductor.
2. Graphite: Layered, hexagonal structure. It is soft, slippery, and an excellent conductor of
electricity due to free electrons.
3. Fullerenes: Carbon atoms arranged in the shape of a football (Example: C-60).
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SECTION 3: HOMOLOGOUS SERIES & NOMENCLATURE
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* Homologous Series (समजातीय श्रेणी):
A series of carbon compounds having the same functional group, where successive
members differ by a "-CH₂-" group and 14 mass units.
- Example of Alkane Series: CH₄ (Methane), C₂H₆ (Ethane), C₃H₈ (Propane).
- Properties: Members show similar chemical properties, but physical properties (like
melting point) change gradually with increasing molecular mass.
* Functional Groups (प्रकार्यात्मक समह
ू ):
An atom or a group of atoms that decides the chemical properties of a carbon compound.
1. Alcohol: -OH (Suffix: -ol)
2. Aldehyde: -CHO (Suffix: -al)
3. Ketone: -CO- (Suffix: -one)
4. Carboxylic Acid: -COOH (Suffix: -oic acid)
5. Halogens: -Cl, -Br (Prefix: Chloro-, Bromo-)
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SECTION 4: CHEMICAL PROPERTIES OF CARBON COMPOUNDS
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1. Combustion (दहन):
- Burning carbon compounds in the presence of oxygen releases Carbon Dioxide, Water,
👉
Heat, and Light.
CH₄ + 2O₂ → CO₂ + 2H₂O + Heat + Light
- Saturated hydrocarbons burn with a clean blue flame. Unsaturated hydrocarbons burn
with a yellow smoky flame.
2. Oxidation (ऑक्सीकरण):
Carbon and its Compounds (Complete Ultra-Detailed Revision Notes)
====================================================================
SECTION 1: INTRODUCTION TO CARBON & COVALENT BONDING
====================================================================
* Occurrence of Carbon:
- Carbon is a versatile element found in very small amounts but holds immense importance.
- In the Earth's crust, it is present as minerals (0.02% like carbonates, coal, petroleum).
- In the atmosphere, it is present as Carbon Dioxide gas (0.03%).
- All living structures (plants, animals, humans) are carbon-based organic matter.
* Versatility of Carbon (Atomic Number = 6):
- Electronic Configuration of Carbon is 2, 4. It has 4 valence electrons.
- To attain a stable noble gas configuration, it needs to either gain 4 electrons or lose 4
electrons.
- Why Carbon cannot form C4+ or C4- ions?
1. It cannot gain 4 electrons (C4-) because it would be difficult for 6 protons in the nucleus
to hold 10 electrons.
2. It cannot lose 4 electrons (C4+) because it requires a huge amount of energy to remove
👉
4 electrons from the atom.
Solution: Carbon shares its valence electrons with other atoms.
* 🤝 Covalent Bond (सहसंयोजक बंध):
- The chemical bond formed by the sharing of electrons between two atoms is called a
Covalent Bond.
- Examples of Single Covalent Bonds: Hydrogen molecule (H₂), Water (H₂O), Ammonia
(NH₃), Methane (CH₄).
- Example of Double Covalent Bond: Oxygen molecule (O₂), Carbon Dioxide (CO₂).
- Example of Triple Covalent Bond: Nitrogen molecule (N₂).
* Properties of Covalent Compounds:
1. Low Melting and Boiling Points: Because the intermolecular forces between the
molecules are very weak.
2. Poor Conductors of Electricity: As electrons are shared, no charged particles or free ions
are formed to conduct current.
====================================================================
SECTION 2: VERSATILE NATURE OF CARBON & HYDROCARBONS
====================================================================
Carbon forms millions of compounds due to two unique chemical properties:
1. Catenation (श्रख
ं ृ लन): Carbon has the unique ability to form strong covalent bonds with
other carbon atoms, giving rise to long straight chains, branched chains, or closed rings.
2. Tetravalency (चतःु संयोजकता): Since carbon has a valency of 4, it can bond with four other
carbon atoms or atoms of elements like Oxygen, Hydrogen, Nitrogen, and Sulphur.
, * HYDROCARBONS (यौगिक जो केवल कार्बन और हाइड्रोजन से बने हैं):
1. Saturated Hydrocarbons (संतप्ृ त - Alkanes): Contains only Single bonds between carbon
atoms.
- General Formula: CnH2n+2 (Examples: Methane CH₄, Ethane C₂H₆).
2. Unsaturated Hydrocarbons (असंतप्ृ त - Alkenes & Alkynes): Contains Double or Triple
bonds.
- Alkenes (Double bond): General Formula is CnH2n (Example: Ethene C₂H₄).
- Alkynes (Triple bond): General Formula is CnH2n-2 (Example: Ethyne C₂H₂).
* Allotropes of Carbon (कार्बन के विभिन्न रूप):
The same element existing in different physical forms with similar chemical properties.
1. Diamond: Three-dimensional rigid network. It is the hardest known natural substance.
Poor conductor.
2. Graphite: Layered, hexagonal structure. It is soft, slippery, and an excellent conductor of
electricity due to free electrons.
3. Fullerenes: Carbon atoms arranged in the shape of a football (Example: C-60).
====================================================================
SECTION 3: HOMOLOGOUS SERIES & NOMENCLATURE
====================================================================
* Homologous Series (समजातीय श्रेणी):
A series of carbon compounds having the same functional group, where successive
members differ by a "-CH₂-" group and 14 mass units.
- Example of Alkane Series: CH₄ (Methane), C₂H₆ (Ethane), C₃H₈ (Propane).
- Properties: Members show similar chemical properties, but physical properties (like
melting point) change gradually with increasing molecular mass.
* Functional Groups (प्रकार्यात्मक समह
ू ):
An atom or a group of atoms that decides the chemical properties of a carbon compound.
1. Alcohol: -OH (Suffix: -ol)
2. Aldehyde: -CHO (Suffix: -al)
3. Ketone: -CO- (Suffix: -one)
4. Carboxylic Acid: -COOH (Suffix: -oic acid)
5. Halogens: -Cl, -Br (Prefix: Chloro-, Bromo-)
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SECTION 4: CHEMICAL PROPERTIES OF CARBON COMPOUNDS
====================================================================
1. Combustion (दहन):
- Burning carbon compounds in the presence of oxygen releases Carbon Dioxide, Water,
👉
Heat, and Light.
CH₄ + 2O₂ → CO₂ + 2H₂O + Heat + Light
- Saturated hydrocarbons burn with a clean blue flame. Unsaturated hydrocarbons burn
with a yellow smoky flame.
2. Oxidation (ऑक्सीकरण):
