Lesson 3.3.9.1

3.3.9.1 Carboxylic acids and esters Quiz: AQA Chemistry, Unit 3

20 questions

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Lesson 3.3.9.1, Carboxylic acids and esters: 20 multiple choice questions for the AQA Chemistry (7405), Unit 3: Organic chemistry, written with Revision Ninja.

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The 20 questions

  1. Which functional group defines an ester?

    • -COO- (carboxylate linkage between C and O)
    • -COOH (carboxylic acid group), which contains both a C=O and an O-H group
    • -CO- (ketone group), in which the carbonyl carbon is bonded to two carbon atoms
    • -OH (hydroxyl group), which is found in alcohols and phenols but not esters
  2. What is the other product when a carboxylic acid and an alcohol form an ester with an acid catalyst?

    • Carbon dioxide
    • Sodium chloride
    • Water
    • Hydrogen
  3. Vegetable oils and animal fats are esters of which alcohol?

    • Methanol, which is used in biodiesel production to form methyl esters from the oils
    • Ethane-1,2-diol, a diol that forms the ester alcohol part of biodiesel
    • Propane-1,2,3-triol (glycerol)
    • Propan-1-ol, a primary alcohol that is used in soap making from fats and oils
  4. Biodiesel is produced by reacting vegetable oils with which alcohol in the presence of a catalyst?

    • Butan-1-ol
    • Propan-2-ol
    • Methanol
    • Ethanol
  5. What products form when a fat is hydrolysed under alkaline conditions?

    • Polyester and water, formed by condensation of the fat with a diol monomer
    • Soap (salts of long-chain carboxylic acids) and glycerol
    • Ethanoic acid and ethanol, formed when the fat is hydrolysed by dilute acid
    • Biodiesel and water, formed when the fat reacts with methanol in a catalysed process
  6. Which compound is formed from ethanoic acid and ethanol with an acid catalyst?

    • Ethyl ethanoate
    • Propyl ethanoate
    • Methyl propanoate
    • Ethyl methanoate
  7. What products form when ethyl ethanoate is hydrolysed in dilute acid?

    • Ethanoic acid and ethanol
    • Ethanal and water
    • Ethene and ethanoic acid
    • Sodium ethanoate and ethanol
  8. What products form when ethyl ethanoate is heated with aqueous sodium hydroxide?

    • Ethanoic acid and sodium ethanol
    • Ethanol and carbon dioxide
    • Sodium ethanoate and ethanol
    • Ethanal and sodium hydroxide
  9. What is the relative molecular mass of ethyl ethanoate, C4H8O2, using Ar C = 12, H = 1 and O = 16?

    • 88
    • 60
    • 102
    • 74
  10. How many fatty acid molecules are released when one triglyceride is fully hydrolysed in alkali?

    • 4
    • 3
    • 1
    • 2
  11. How many methanol molecules react with one triglyceride to form biodiesel?

    • 2
    • 1
    • 4
    • 3
  12. Why does ethyl ethanoate have a lower boiling point than ethanoic acid of similar molar mass?

    • Ethanoic acid is an ionic compound with stronger attractions between its molecules
    • Ethyl ethanoate has a larger molecular mass than ethanoic acid of similar size
    • Ethyl ethanoate cannot form hydrogen bonds between its molecules, unlike the acid
    • Ethyl ethanoate cannot form hydrogen bonds between its molecules, unlike ethanoic acid
  13. Which ester is formed from propanoic acid and butan-1-ol?

    • Butyl ethanoate
    • Propyl propanoate
    • Butyl propanoate
    • Propyl butanoate
  14. How can the yield of an ester from an acid and an alcohol be increased?

    • Add more acid catalyst only
    • Increase the pressure to above 100 atm
    • Use excess alcohol or remove water as it forms
    • Use an excess of the ester product at the start
  15. What is the name for the alkaline hydrolysis of a fat to make soap?

    • Esterification
    • Saponification
    • Halogenation
    • Hydration
  16. Why is a separating funnel used after making an ester in the laboratory?

    • To heat the reaction mixture under reflux so that the ester boils off as a gas
    • To filter off solid catalyst particles that would otherwise contaminate the ester
    • To measure the boiling point of the ester by collecting the first drops of distillate
    • To separate the less dense ester layer from the aqueous layer
  17. Ethanoic acid (0.10 mol) reacts with excess ethanol and forms 0.06 mol of ethyl ethanoate. What is the percentage yield?

    • 40%
    • 60%
    • 100%
    • 6%
  18. Which equation shows the esterification of ethanoic acid with methanol?

    • CH3COOH + CH3OH -> CH3CH2OH + H2O
    • CH3COOH + CH3OH -> CH3COOCH3 + H2O
    • CH3COOH + CH3OH -> CH3COCH3 + H2O
    • CH3COOH + CH3OH -> CH3COOH2 + OH
  19. Why are vegetable oils and fats called triglycerides?

    • Each glycerol molecule carries three ester groups, one from each fatty acid
    • Each triglyceride contains three benzene rings
    • Each triglyceride has three carbonyl groups that are ketones
    • Each triglyceride contains three different alcohols
  20. Which statement about the alkaline hydrolysis of ethyl ethanoate is correct?

    • It is reversible and gives a stable equilibrium mixture that always contains some ester
    • It needs an acid catalyst to proceed at all, and without one no reaction takes place
    • It goes to completion because the carboxylate salt formed is not easily converted back to the ester
    • It produces an ether as the main organic product, with the acid as a minor by-product

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