Latest Updated CBSE Class 10 Science CH-04 Carbon and its Compounds

November 24, 2024 ,

CBSE Class 10 Science Notes Chapter 4 Carbon and its Compounds For 2025 Board Examination


CBSE Class 10 Science Notes: Chapter 4 - Carbon and its Compounds

Key Points:

  1. Covalent Bonding:

    • Carbon forms covalent bonds by sharing electrons with other elements to complete its octet.
    • Examples: Methane (CH₄) and ethene (C₂H₄).

  2. Versatile Nature of Carbon:

    • Tetravalency: Forms four bonds with other atoms.
    • Catenation: Self-linking property to form chains, branches, or rings.
    • Forms single, double, or triple bonds.

  3. Hydrocarbons:

    • Saturated (Alkanes): Single bonds, e.g., Methane.
    • Unsaturated:
      • Alkenes: Double bonds, e.g., Ethene.
      • Alkynes: Triple bonds, e.g., Ethyne.

  4. Functional Groups:

    • Oxygen-containing groups: Alcohol (-OH), Aldehyde (-CHO), Ketone (-CO-), Carboxylic acid (-COOH).
    • Halogens (-Cl, -Br, etc.).

  5. Chemical Properties:

    • Combustion: Carbon compounds burn to form CO₂ and water, releasing heat.
    • Oxidation: Alcohols to acids using oxidizing agents.
    • Addition Reaction: Unsaturated hydrocarbons react with hydrogen in the presence of a catalyst to form saturated hydrocarbons.
    • Substitution Reaction: Replacement of hydrogen in alkanes by halogens.

  6. Homologous Series:

    • A series of compounds differing by a -CH₂ group.
    • Example: Methanol (CH₃OH), Ethanol (C₂H₅OH).
    • Shows similar chemical properties and gradation in physical properties.

  7. Soaps and Detergents:

    • Soap: Sodium or potassium salts of fatty acids. Cleans by forming micelles.
    • Detergents: Synthetic compounds effective in hard water.

Important Diagrams:

  • Structure of methane, ethene, ethyne.
  • Micelle formation (soap molecule mechanism).

Applications:

  • Fuels, cleaning agents, plastics, and medicines.

Updated 2025 Board Examination Most Important Science Class 10 Questions Answers 

Top Asked Questions and Answers: Chapter 4 - Carbon and its Compounds (CBSE Class 10)

  1. Why is carbon versatile?
    Carbon is versatile due to:

    • Tetravalency: Forms four covalent bonds.
    • Catenation: Ability to form long chains or rings.

  2. What are homologous series? Give examples.
    A homologous series is a group of organic compounds with the same functional group, differing by a -CH₂ unit.
    Example: Alkanes (Methane CH₄, Ethane C₂H₆).

  3. Differentiate between soaps and detergents.

    • Soaps: Sodium/potassium salts of fatty acids; ineffective in hard water.
    • Detergents: Synthetic compounds; effective in hard water.

  4. Explain the combustion of carbon compounds.
    Combustion produces CO₂, water, and heat. Example:
    CH₄ + 2O₂ → CO₂ + 2H₂O + Heat.

  5. What are addition and substitution reactions?

    • Addition: Unsaturated hydrocarbons react with H₂ (catalyst) to form saturated compounds.
    • Substitution: Replacement of hydrogen by halogens in saturated hydrocarbons.

Updated 2025 Most Important MCQs Science Class 10 

MCQs on Chapter 4: Carbon and its Compounds

  1. Which property allows carbon to form a large number of compounds?
    a) Tetravalency
    b) Catenation
    c) Both a and b
    d) None of these
    Answer: c) Both a and b

  2. Which of the following is the general formula for alkanes?
    a) CₙH₂ₙ
    b) CₙH₂ₙ₊₂
    c) CₙH₂ₙ₋₂
    d) CₙH₂ₙ₊₁
    Answer: b) CₙH₂ₙ₊₂

  3. What type of reaction occurs when ethene reacts with hydrogen in the presence of a catalyst?
    a) Substitution reaction
    b) Addition reaction
    c) Combustion reaction
    d) Oxidation reaction
    Answer: b) Addition reaction

  4. Which of the following is not a functional group?
    a) -OH
    b) -COOH
    c) -COO
    d) -CHO
    Answer: c) -COO

  5. What is the main product formed when ethanol is oxidized by acidified potassium dichromate?
    a) Ethane
    b) Ethanoic acid
    c) Methanoic acid
    d) Acetaldehyde
    Answer: b) Ethanoic acid

  6. The formula of soap is represented by:
    a) R-COONa
    b) R-COOH
    c) R-OH
    d) R-CHO
    Answer: a) R-COONa

  7. Which of the following is not a saturated hydrocarbon?
    a) Propane
    b) Butane
    c) Ethene
    d) Methane
    Answer: c) Ethene

  8. What happens when sodium reacts with ethanol?
    a) Hydrogen gas is evolved
    b) Sodium ethoxide is formed
    c) Both a and b
    d) Sodium hydroxide is formed
    Answer: c) Both a and b

  9. The homologous series of alcohols has the functional group:
    a) -COOH
    b) -OH
    c) -CHO
    d) -CO
    Answer: b) -OH

  10. Which reaction helps in the preparation of ethanol from ethene?
    a) Substitution reaction
    b) Addition reaction with steam
    c) Oxidation
    d) Reduction
    Answer: b) Addition reaction with steam

Board Exam Class 10 Science Revision Notes




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