Lesson 4.2.3

4.2.3 Organic synthesis Quiz: OCR Chemistry, Unit 3

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 4.2.3, Organic synthesis: 20 multiple choice questions for the OCR Chemistry (H432), Unit 3: Core organic chemistry, written with Revision Ninja.

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The 20 questions

  1. What is the primary purpose of distillation using Quickfit apparatus?

    • Reflux volatile compounds
    • Dry organic liquids
    • Test for unsaturation
    • Separate liquid mixtures

  2. What is the main purpose of heating a reaction mixture under reflux?

    • Separate immiscible liquids
    • Remove water traces
    • Prevent vapour loss
    • Distil off products

  3. What is a separating funnel used for during organic liquid purification?

    • Distilling volatile products
    • Separating immiscible liquids
    • Refluxing reaction mixtures
    • Drying organic liquids

  4. What is the function of anhydrous magnesium sulfate in organic purification?

    • Removing unreacted alkene
    • Catalysing ester hydrolysis
    • Neutralising acidic impurities
    • Drying organic liquids

  5. What is the main purpose of redistillation during organic synthesis?

    • Purifying the product
    • Preventing vapour loss
    • Removing drying agents
    • Dehydrating primary alcohols

  6. Which compound contains an ester functional group?

    • Ethanal, CH3CHO
    • Ethyl ethanoate, CH3COOCH2CH3
    • Ethanol, CH3CH2OH
    • Ethanoic acid, CH3COOH

  7. Which reagent is used to test for the presence of a C=C double bond?

    • Acidified potassium dichromate
    • Tollens' reagent
    • Bromine water
    • Sodium carbonate solution

  8. Which initial reagent converts bromoethane to ethanol in a two-stage synthesis to ethanoic acid?

    • Aqueous sodium hydroxide
    • Acidified potassium dichromate
    • Concentrated sulfuric acid
    • Ethanolic sodium hydroxide

  9. Which practical technique is required when oxidising propan-1-ol directly to propanal?

    • Reflux
    • Filtration
    • Distillation
    • Recrystallisation

  10. What type of reaction converts ethanol into ethene prior to bromination?

    • Elimination
    • Substitution
    • Oxidation
    • Addition

  11. Two stages of a synthesis have yields of 80% and 75%. What is the overall percentage yield?

    • 80%
    • 65%
    • 55%
    • 60%

  12. How many functional groups are present in CH2=CHCOOH?

    • 1
    • 4
    • 2
    • 3

  13. Which compound is most reactive towards bromine water?

    • But-1-ene
    • Butane
    • 2-methylbutane
    • Cyclobutane

  14. How should a Liebig condenser be fitted to a flask when heating under reflux?

    • Horizontally
    • Directly downward
    • At an angle
    • Vertically

  15. How is a carboxyl group written in a structural formula?

    • CO2H only
    • CHO
    • CO
    • COOH

  16. Which substance is removed from an organic product when a drying agent is added?

    • Acidic catalyst
    • Water
    • Ethanol
    • Unreacted alkane

  17. Which physical property allows redistillation to separate a desired organic liquid from impurities?

    • Water solubility
    • Boiling point
    • Relative density
    • Melting point

  18. Which functional group is formed when ethanoic acid and ethanol are heated together with an acid catalyst?

    • Haloalkane
    • Ester
    • Ketone
    • Aldehyde

  19. Which reagent and condition convert a bromoalkane into an alcohol?

    • Concentrated H2SO4
    • Warm ethanolic NaOH
    • Warm aqueous NaOH
    • Cold aqueous HCl

  20. Which reaction type converts the intermediate propan-1-ol into propanoic acid?

    • Oxidation
    • Reduction
    • Dehydration
    • Substitution

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