Organic Compounds: JAMB Chemistry Questions, Answers & Notes

What Organic Compounds covers in the JAMB Chemistry syllabus

Organic chemistry is the study of carbon compounds. Hydrocarbons (carbon and hydrogen only) form homologous series with general formulae and graded properties: alkanes (CₙH₂ₙ₊₂, saturated, single bonds; e.g. methane), alkenes (CₙH₂ₙ, unsaturated with a C=C, decolourise bromine water) and alkynes (CₙH₂ₙ₋₂, C≡C). Functional-group families include alcohols/alkanols (–OH, e.g. ethanol from fermentation) and alkanoic acids (–COOH); an acid + alcohol gives an ester (esterification). Isomers share a molecular formula but differ in structure. Cracking breaks large molecules into useful smaller ones, and monomers like ethene join to form polymers such as polythene. Complete combustion gives CO₂ and water.

For Organic Compounds, JAMB expects you to be able to:

• Define organic chemistry, hydrocarbons and homologous series
• Distinguish alkanes, alkenes and alkynes and their general formulae
• Describe alcohols, acids, esters, isomerism, cracking and polymers

Key facts & revision notes: Organic Compounds

These are the recurring points our Organic Compounds questions test — revise them until each feels automatic, then practise the questions above to lock them in.

• Organic chemistry is the chemistry of carbon compounds.
• Hydrocarbons contain only carbon and hydrogen.
• Alkanes have the general formula CₙH₂ₙ₊₂ (saturated hydrocarbons).
• Methane, CH₄, is the simplest alkane.
• Saturated hydrocarbons (alkanes) contain only single carbon–carbon bonds.
• Alkenes have the general formula CₙH₂ₙ and contain a C=C double bond.
• Alkenes are unsaturated — they contain at least one C=C double bond.
• Alkenes decolourise bromine water (addition across the double bond); alkanes do not.
• A homologous series shares a general formula and similar chemical properties, differing by CH₂.
• Cracking breaks large hydrocarbon molecules into smaller, more useful ones (e.g.
• Ethanol is an alkanol (alcohol); its functional group is –OH.
• Alkanoic acids contain the carboxyl group, –COOH.
• Fermentation of sugars by yeast produces ethanol and carbon dioxide.
• Complete combustion of a hydrocarbon gives carbon dioxide and water.
• Isomers have the same molecular formula but different structural arrangements.
• Esterification: an alkanoic acid + an alcohol → an ester (sweet-smelling) + water.
• Polymers are built from many repeating small units called monomers.
• Polythene is formed by the addition polymerisation of ethene molecules.
• Natural gas and petroleum (crude oil) are mixtures of hydrocarbons.
• Alkynes have the general formula CₙH₂ₙ₋₂ and contain a carbon–carbon triple bond.
• Ethane, C₂H₆, is the second alkane.
• Using CₙH₂ₙ₊₂ with n = 2 gives C₂H₆.
• CₙH₂ₙ₊₂ with n = 3 gives C₃H₈.
• Alkenes start at ethene; there is no 'methene'.

Worked examples

Three Organic Compounds questions with the answer and a short explanation, so you can see how the topic is set before you practise the full set.

How Organic Compounds is tested in JAMB Chemistry

Our Organic Compounds bank holds 40 questions (4 easy, 24 medium, 12 hard). JAMB Chemistry typically returns to Organic Compounds year after year, so steady practice on this topic is high-value revision. Questions are multiple-choice with four options, and at UTME pace you get roughly 40 seconds each — which is why timed practice matters.

How to answer Organic Compounds questions

Work the stem first and predict the answer before you look at the options; then eliminate the ones that contradict the key facts above. Watch for “which is not…”, “all of the above” and “except” style stems, which are where rushed candidates lose easy marks on Organic Compounds. If a calculation or a precise definition is involved, work it from first principles rather than guessing from a half-remembered rule. When two options look right, re-read the stem for the qualifier that separates them — JAMB rarely repeats an option by accident. If you are still unsure, eliminate the two weakest choices to lift your odds, flag the question, and move on; never burn a full minute on one Chemistry item when the exam gives you about forty seconds each. Then come back to flagged questions with whatever time remains. The single most reliable way to get faster at Organic Compounds is repeated timed practice, so use the button above until the recurring patterns feel automatic.

Common mistakes to avoid in Organic Compounds

The errors that cost marks on Organic Compounds are usually careless rather than conceptual: misreading a negative stem, confusing two similar terms, or rushing a definition you actually know. Candidates also over-rely on “expo” and last-minute cramming instead of understanding the topic — which fails the moment JAMB rephrases a familiar idea. Treat every option as a claim to be checked against the facts above, keep your working tidy for any calculation, and don’t change a considered answer on a hunch. Above all, revise Organic Compounds actively by answering questions, not just by re-reading notes — recall under time is what the exam rewards.

Frequently asked questions

Is Organic Compounds part of the JAMB Chemistry syllabus?

Yes. Organic Compounds is a recognised topic in the JAMB Chemistry syllabus, covering define organic chemistry, hydrocarbons and homologous series. You should be able to recall its key facts and apply them to multiple-choice questions.

How many Organic Compounds questions can I practise on Belmadeng?

There are 40 original, JAMB-standard Organic Compounds questions in our free bank, each with the correct answer and a worked explanation. You can practise them untimed or as a timed test.

What are the most important points to know about Organic Compounds?

Organic chemistry is the study of carbon compounds. Hydrocarbons (carbon and hydrogen only) form homologous series with general formulae and graded properties: alkanes (CₙH₂ₙ₊₂, saturated, single bonds; e.g. methane), alkenes (CₙH₂ₙ, unsaturated with a C=C, decolourise bromine water) and alkynes (Cₙ…

How do I answer Organic Compounds questions quickly in JAMB?

Read the stem carefully, eliminate clearly wrong options, and match the remaining choices to the key facts for Organic Compounds. Practising timed Organic Compounds questions builds the speed you need for UTME's pace of about 40 seconds per question.

Are these JAMB Chemistry Organic Compounds questions past questions or original?

They are original questions written to JAMB (UTME) standard and mapped to the official syllabus — not reproduced past papers. This keeps them legal to use freely while closely mirroring how the real exam tests the topic.

Where can I practise Organic Compounds questions free without signing up?

Right here — tap “Start Organic Compounds practice” on this page to begin instantly. Belmadeng's CBT practice is completely free and needs no sign-up, download or subscription.

About these questions: original, JAMB-standard items written from the official UTME Chemistry syllabus (last reviewed 2026-09-18). Belmadeng is an independent study platform and is not affiliated with JAMB. Spotted an error? Use the report link.