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Class 10 Science — Carbon and its compounds

Explain why carbon shares electrons rather than trading them, tell a saturated compound from an unsaturated one, work along a homologous series, and name what soap does to oily dirt.

Name: ________________________

  1. 1.An unsaturated hydrocarbon is warmed with hydrogen over a palladium catalyst. What comes out?

    • a) A saturated hydrocarbon
    • b) A carboxylic acid
    • c) An ester
    • d) A haloalkane

  2. 2.Vegetable oil is hydrogenated with a nickel catalyst. What does the nickel do?

    • a) It removes the double bonds by dissolving them
    • b) It is used up as one of the reactants
    • c) It joins the oil molecule in place of a hydrogen
    • d) It makes the reaction go without being changed itself

  3. 3.Put the saturated chains in order of how many carbon atoms they hold, fewest first, beginning with "Methane".

    • Butane
    • Methane
    • Pentane
    • Propane
    • Hexane
    • Ethane

  4. 4.Why does carbon share electrons instead of gaining or losing four of them?

    • a) Carbon atoms are too large to hold a charge
    • b) Carbon has no electrons in its outermost shell to give away
    • c) Six protons could neither hold ten electrons nor be stripped of four without great cost
    • d) Carbon already has a full outermost shell

  5. 5.Why do detergents go on working in hard water where soap does not?

    • a) They soften the water before they clean
    • b) They dissolve the calcium and magnesium salts completely
    • c) Their charged ends do not form insoluble precipitates with calcium and magnesium ions
    • d) They are made without a hydrocarbon chain

  6. 6.Ethanoic acid is warmed with ethanol and a little concentrated sulphuric acid, and the mixture ends up smelling sweet. What is the sweet-smelling product called? Answer with one word.

  7. 7.Sort each compound by whether it carries a double or triple bond between carbon atoms.

    Groups: Saturated · Unsaturated

    • Propene
    • Ethene
    • Methane
    • Ethyne
    • Cyclohexane
    • Ethane

  8. 8.Methane and chlorine are left together in sunlight, and one hydrogen of the methane is replaced by a chlorine atom. What kind of reaction is this?

    • a) An oxidation reaction
    • b) An addition reaction
    • c) An esterification reaction
    • d) A substitution reaction

Answer key — Class 10 Science — Carbon and its compounds

  1. 1. a) A saturated hydrocarbon
  2. 2. d) It makes the reaction go without being changed itself
  3. 3. 1. Methane 2. Ethane 3. Propane 4. Butane 5. Pentane 6. Hexane
  4. 4. c) Six protons could neither hold ten electrons nor be stripped of four without great cost
  5. 5. c) Their charged ends do not form insoluble precipitates with calcium and magnesium ions
  6. 6. ester
  7. 7. Methane → Saturated; Ethane → Saturated; Cyclohexane → Saturated; Ethene → Unsaturated; Ethyne → Unsaturated; Propene → Unsaturated
  8. 8. d) A substitution reaction