Class 10 Science – Mock Test Paper Chapter: Carbon and Its Compounds


๐Ÿ“ Class 10 Science – Mock Test Paper

Chapter: Carbon and Its Compounds
Maximum Marks: 30
Time: 1½ hours


Section – A (1 × 5 = 5 marks)

  1. Write the molecular formula of propane.
  2. What is the functional group of alcohol?
  3. Name the product formed when ethanol is heated with excess concentrated H₂SO₄ at 443 K.
  4. State the reaction observed when acetic acid is added to NaHCO₃ solution.
  5. Write the structural formula of ethyne.

Section – B (2 × 3 = 6 marks)

  1. Why does carbon form compounds mainly by covalent bonding?
  2. Differentiate between soaps and detergents.
  3. Write the reaction of saponification and name the products formed.

Section – C (3 × 4 = 12 marks)

  1. Draw the electron dot structure of methane (CH₄).
  2. State three characteristics of a homologous series with an example.
  3. Explain the mechanism of cleaning action of soap with the help of a labeled diagram.
  4. Write chemical equations for the following reactions:
    (i) Oxidation of ethanol
    (ii) Esterification of ethanol with acetic acid
    (iii) Reaction of ethanoic acid with NaOH

Section – D (5 × 1 = 5 marks)

  1. (a) What is hydrogenation reaction? Explain with an example and state its industrial application.
    (b) Give two differences between saturated and unsaturated hydrocarbons.

Marking Scheme (Suggested Answers)

Section A:

  1. C₃H₈
  2. –OH
  3. Ethene (C₂H₄)
  4. CO₂ gas evolves (effervescence)
  5. HC≡CH

Section B:
6. Carbon has 4 valence electrons → tetravalent → shares electrons → forms covalent bonds.
7. Soaps: Made from vegetable oils/fats, form scum in hard water.
Detergents: Made from petrochemicals, work in hard & soft water.
8. Ester + NaOH → Sodium salt of acid (soap) + Alcohol.

Section C:
9.

  H
  |
H–C–H
  |
  H
  1. Same functional group, same general formula, differ by –CH₂ group, similar chemical properties. Example: CH₄, C₂H₆, C₃H₈.
  2. Soap molecules form micelles → hydrophobic tail traps dirt, hydrophilic head remains in water → grease removed.

(i) C₂H₅OH + [O] → CH₃COOH + H₂O
(ii) CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O
(iii) CH₃COOH + NaOH → CH₃COONa + H₂O

Section D:
13. (a) Addition of hydrogen to unsaturated hydrocarbons in presence of Ni/Pd catalyst. Example: C₂H₄ + H₂ → C₂H₆.
Industrial use: Conversion of vegetable oil to ghee.
(b) Saturated: Single bonds, less reactive. Unsaturated: Double/triple bonds, more reactive.



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