10 free AS Level Chemistry Organic Chemistry questions written in the style of Cambridge Chemistry papers: 4 multiple-choice and 6 structured, each with its answer and mark scheme. 4 of them are A* challenge questions, built to catch the mistakes strong students still make.
This topic covers Introduction to organic chemistry, Hydrocarbons, Halogen compounds, Hydroxy compounds, Carbonyl compounds, Carboxylic acids & derivatives, Nitrogen compounds, Polymerisation, Organic synthesis, Analytical techniques. Work through the questions below, then generate a full Organic Chemistry paper with a fresh set every time.
Generate a full Organic Chemistry paper →Which row shows the results of tests on propanone?
| 2,4-DNPH | Tollens’ reagent | alkaline aqueous iodine | |
|---|---|---|---|
| A | orange precipitate | no change | yellow precipitate |
| B | orange precipitate | silver mirror | yellow precipitate |
| C | no change | no change | yellow precipitate |
| D | orange precipitate | no change | no yellow precipitate |
Answer: A
Which alcohol cannot be oxidised by acidified potassium dichromate(VI)?
Answer: A
What type of polymerisation forms poly(ethene)?
Answer: C
Which compound is a primary amine?
Answer: B
Carbonyl compounds undergo nucleophilic addition with HCN.
Describe the mechanism for the reaction of ethanal with HCN.
Explain why the product from propanal is a racemic mixture.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | CN⁻ attacks δ+ C; intermediate; protonated CN⁻ attacks δ+ carbon B1 curly arrow C=O to O B1 anion intermediate B1 protonated by H⁺/HCN B1 | 4 |
| (b) | planar C=O attacked from either side carbonyl group is planar B1 equal chance of attack from either side giving both enantiomers B1 | 2 |
Compound X contains carbon, hydrogen and oxygen only. It contains 54.5% C and 9.1% H by mass. In its mass spectrum, the molecular ion peak is at m/e = 88 and the M+1 peak has 4.4% of the abundance of the M peak. X shows a strong IR absorption at 1740 cm−1 and no broad absorption above 2500 cm−1.
Calculate the empirical formula of X.
Use the M+1 peak to confirm the number of carbon atoms, and deduce the molecular formula.
Use the infrared data to identify the functional group, and suggest two possible structures for X.
X is hydrolysed by heating with dilute acid. One product is ethanol. Identify X and write the equation for the hydrolysis.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | C2H4O % O = 36.4 C1 mole ratio 4.54 : 9.1 : 2.27 C1 C2H4O A1 | 3 |
| (b) | 4 carbon atoms; C4H8O2 4.4 ÷ 1.1 = 4 B1 C4H8O2 B1 | 2 |
| (c) | ester (C=O at 1740, no O–H); e.g. ethyl ethanoate CH3COOCH2CH3 and methyl propanoate CH3CH2COOCH3 ester B1 first correct structure B1 second correct structure B1 | 3 |
| (d) | ethyl ethanoate; CH3COOC2H5 + H2O ⇌ CH3COOH + C2H5OH ethyl ethanoate B1 balanced equation B1 | 2 |
Propene can be converted into several products.
reaction 1: propene + HBr → compound A (major product)
reaction 2: A + NaOH(aq), heat → compound B
reaction 3: B + acidified K2Cr2O7, heat → compound C
reaction 4: C + 2,4-DNPH → orange precipitate; C does not react with Tollens’ reagent.
Name compounds A, B and C.
Describe the mechanism of reaction 1, including the intermediate, and explain why A is the major product.
Name the type of reaction in reaction 2 and state why reaction 3 does not go further.
Give the structural formula of the organic product formed when C reacts with alkaline aqueous iodine, and state the observation.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | A 2-bromopropane; B propan-2-ol; C propanone 2-bromopropane B1 propan-2-ol B1 propanone B1 | 3 |
| (b) | electrophilic addition; curly arrow from C=C to H of HBr, H–Br heterolysis; secondary carbocation; Br− attacks; secondary carbocation more stable (more electron-donating alkyl groups) curly arrow from π bond to H M1 H–Br bond breaking to Br M1 secondary carbocation drawn A1 Br− attacks carbocation M1 secondary carbocation more stable (inductive effect) B1 | 5 |
| (c) | nucleophilic substitution; ketone (secondary alcohol product) is not oxidised further nucleophilic substitution B1 ketone cannot be oxidised (no H on carbonyl carbon) B1 | 2 |
| (d) | CHI3 (and CH3COO−); yellow precipitate CHI3 B1 yellow precipitate B1 | 2 |
Infrared spectroscopy and mass spectrometry identify organic compounds.
State the absorption ranges that identify O–H in an alcohol and C=O.
A mass spectrum shows M and M+1 peaks in the ratio 100 : 3.3. Deduce the number of carbon atoms.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | 3200–3600; 1680–1750 O–H 3200–3600 cm−1 B1 C=O 1680–1750 cm−1 B1 | 2 |
| (b) | 3 n = (3.3/100) × (100/1.1) C1 3 A1 | 2 |
Halogenoalkanes can undergo elimination.
State the conditions for elimination rather than substitution.
Name the organic product when 2-bromopropane undergoes elimination.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | ethanolic NaOH; heat NaOH in ethanol B1 heat B1 | 2 |
| (b) | propene propene B1 | 1 |
Aldehydes and ketones can be distinguished by chemical tests.
Describe how Tollens’ reagent distinguishes propanal from propanone.
Describe the reagent used to show that both contain a carbonyl group, and the result.
| Part | Answer and marking points | Marks |
|---|---|---|
| (a) | silver mirror with aldehyde warm with Tollens’ reagent B1 silver mirror with propanal, no change with propanone B1 | 2 |
| (b) | 2,4-DNPH orange precipitate 2,4-dinitrophenylhydrazine B1 orange/yellow precipitate B1 | 2 |
In the 9701 syllabus, Organic Chemistry covers Introduction to organic chemistry, Hydrocarbons, Halogen compounds, Hydroxy compounds, Carbonyl compounds, Carboxylic acids & derivatives, Nitrogen compounds, Polymerisation, Organic synthesis, Analytical techniques.
This page has 10 Organic Chemistry questions with answers. For more, the free generator on mentorriyaz.in builds a new Organic Chemistry paper with a full mark scheme each time you click.
Riyaz Shaikh has mentored IGCSE, IB and A Level students for 15+ years, one-on-one, online and in Mumbai. The hardest questions on this site are the ones he uses to find a student's weak points.
Meet Riyaz →Original Cambridge-style practice questions written for mentorriyaz.in. These are not Cambridge past paper questions, and this site is not affiliated with or endorsed by Cambridge University Press & Assessment. Updated 2026-11-04. Paper generator · mentorriyaz.in