AS Level Chemistry chapter 16: Hydroxy compounds MCQs with answers

By Team Megalecture · Updated 4 Nov 2026

22 exam-style questions on Hydroxy compounds, each with the answer and a short explanation. Ten of them are below to try. The chapter test draws ten fresh questions each time and is marked the moment you finish, with your score by topic.

22 questions · 1 topics · 10 per test

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What chapter 16 covers

Ten Hydroxy compounds questions with answers

Try each one, then open the answer. These ten stay the same; the test draws new ones every time.

1. Which alcohol does NOT give a yellow precipitate when warmed with alkaline aqueous iodine?

  1. A
    ethanol
  2. B
    propan-1-ol
  3. C
    propan-2-ol
  4. D
    butan-2-ol
Show answer

Answer: B. The test needs a CH3CH(OH)– group. Ethanol has one (R = H), as do propan-2-ol and butan-2-ol. In propan-1-ol the OH is on the end carbon, which is CH2 bonded to an ethyl group, so it gives no tri-iodomethane.

2. But-1-ene, CH2=CHCH2CH3, reacts with steam in the presence of phosphoric acid. Which alcohol is the major product?

  1. A
    butan-1-ol
  2. B
    butan-2-ol
  3. C
    2-methylpropan-2-ol
  4. D
    butane-1,2-diol
Show answer

Answer: B. H+ adds to the end CH2 to give the more stable secondary carbocation on C2, and water bonds there, so CH3CH(OH)CH2CH3 is the major product. The diol needs cold, dilute manganate(VII).

3. Which alcohol is not oxidised when warmed with acidified potassium dichromate(VI)?

  1. A
    propan-1-ol
  2. B
    propan-2-ol
  3. C
    2-methylpropan-2-ol
  4. D
    butan-1-ol
Show answer

Answer: C. Oxidation removes the H on the carbon carrying the OH. A tertiary alcohol has no such hydrogen, so the orange dichromate stays orange. Primary alcohols give aldehydes/acids and secondary alcohols give ketones.

4. Which test distinguishes butan-2-ol from 2-methylpropan-2-ol?

  1. A
    warming with acidified potassium dichromate(VI)
  2. B
    adding sodium metal
  3. C
    adding phosphorus(V) chloride
  4. D
    burning in excess oxygen
Show answer

Answer: A. Butan-2-ol is a secondary alcohol and is oxidised, turning the dichromate from orange to green; the tertiary alcohol leaves it orange. Both alcohols fizz with sodium, give HCl fumes with PCl5 and burn completely.

5. Which reaction produces a secondary alcohol?

  1. A
    reduction of propanal with NaBH4
  2. B
    reduction of propanone with NaBH4
  3. C
    hydrolysis of 1-bromopropane with NaOH(aq)
  4. D
    reduction of propanoic acid with LiAlH4
Show answer

Answer: B. Reducing a ketone puts the OH on a carbon already bonded to two other carbons: propanone gives propan-2-ol. The other three all give the primary alcohol propan-1-ol.

6. A carbonyl compound is reduced with NaBH4 to give 2-methylpropan-1-ol, (CH3)2CHCH2OH. What was the carbonyl compound?

  1. A
    butanal
  2. B
    butanone
  3. C
    2-methylpropanal
  4. D
    propanone
Show answer

Answer: C. Reduction keeps the carbon skeleton and turns C=O into CH–OH. A primary alcohol comes from an aldehyde with the same branched chain, (CH3)2CHCHO. Butanone would give the secondary alcohol butan-2-ol.

7. What volume of oxygen, measured at room conditions, is needed to burn 0.0500 mol of propan-1-ol, C3H7OH, completely?

  1. A
    3.60 dm3
  2. B
    4.80 dm3
  3. C
    5.40 dm3
  4. D
    6.00 dm3
Show answer

Answer: C. C3H7OH + 4½O2 → 3CO2 + 4H2O, so 0.0500 × 4.5 × 24.0 = 5.40 dm3. 6.00 dm3 uses 5 O2, forgetting the oxygen atom already in the alcohol.

8. Sodium reacts less vigorously with ethanol than with water. Which statement is correct?

  1. A
    The ethoxide ion, C2H5O−, is a stronger base than the hydroxide ion.
  2. B
    Ethanol is a stronger acid than water.
  3. C
    The ethyl group withdraws electron density from the oxygen atom in ethoxide.
  4. D
    Ethanol has stronger hydrogen bonding than water, so its O–H bond cannot break.
Show answer

Answer: A. The ethyl group pushes electron density onto the O− of ethoxide, so the negative charge is more concentrated and it accepts H+ more readily. Ethanol is therefore the weaker acid and ethoxide the stronger conjugate base.

9. Why is ethanol a weaker acid than water?

  1. A
    ethanol has fewer O–H bonds per molecule
  2. B
    ethanol cannot form hydrogen bonds
  3. C
    the O–H bond in ethanol is much stronger
  4. D
    the ethyl group pushes electron density onto the oxygen, making the ethoxide ion less stable than the hydroxide ion
Show answer

Answer: D. The electron-donating alkyl group increases the negative charge density on the oxygen of C2H5O−, so the ion is less stable and ethanol loses its proton less readily than water. Ethanol still reacts with sodium, but more slowly than water.

10. Ethanol is heated with propanoic acid and a few drops of concentrated sulfuric acid. What is the organic product?

  1. A
    ethyl propanoate, CH3CH2COOCH2CH3
  2. B
    propyl ethanoate, CH3COOCH2CH2CH3
  3. C
    ethyl ethanoate, CH3COOCH2CH3
  4. D
    pentan-3-one, CH3CH2COCH2CH3
Show answer

Answer: A. An alcohol and a carboxylic acid form an ester and water. The name starts with the alcohol part (ethyl) and ends with the acid part (propanoate). Propyl ethanoate swaps the two parts.

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How many Hydroxy compounds MCQs are there?

22, each with the answer and a short explanation, across 1 topics: Alcohols. Every chapter test draws ten of them, so you can take it many times.

Is the AS Level Chemistry chapter 16 test free?

Yes. The test, the answers and the explanations are free and need no sign-up. Sign in only if you want your scores kept across devices.

How is the chapter test marked?

The moment you press Finish: your score, the right answer and an explanation for every question, and the ones you got wrong saved in My mistakes to retry.

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