Pearson Edexcel International GCSE in Chemistry · 4CH1 · Free · no account needed
Alkenes — exam questions
12 original Incandio exam-style questions on alkenes, 26 marks, about 26 minutes of writing. Each one carries the command word, the tariff and the specification statement it assesses, exactly as a paper presents them. This is an original Incandio practice question, written to reflect the structure and demands of the qualification. It is not an official Pearson Edexcel past-paper question.
This is the practice set for Alkenes — the lesson that teaches it. Read the lesson first if the idea is new; come here when you want to find out whether you can turn it into marks. Completely free, no account needed to read.
What these questions ask of you
8 command words run through this set, and on Pearson Edexcel International GCSE Chemistry each one means something precise. Answering the wrong command is the commonest way a candidate who understands the lesson still loses the mark.
- Which (1 mark)
- one option chosen from the set given
- Give (1–2 marks)
- a short factual answer — the most common chemistry command
- State what is meant by (1–2 marks)
- the definition
- Determine (1–4 marks)
- a value reached by combining given data with a method the learner selects
- Explain (2–4 marks)
- the reason, in terms of particles, bonding, energy or equilibrium Misread as: describing the observation without giving the chemistry that causes it
- Compare (2–4 marks)
- explicit comparison with a comparative word — a bare pair of statements is not a comparison
- Suggest (1–3 marks)
- a plausible answer applying taught chemistry to an unfamiliar substance
- Complete (1–4 marks)
- the missing entries in a table, equation or diagram
Assessed on Paper 1 (4CH1/1C) and Paper 2 (4CH1/2C), against AO1, AO2, AO3.
Where these sit in the specification
Pearson Edexcel International GCSE Chemistry (4CH1) — statements 4.23 · 4.24 · 4.25 · 4.26. Incandio is aligned to this specification; it is not published by, endorsed by or affiliated with Pearson, and it reproduces none of Pearson's wording.
The 12 questions
Answer them on paper, then open the lesson's exam practice to have them marked. The mark scheme, the accepted and rejected answers and the annotated model answer are in Incandio and are not printed here — an answer beside its question is not practice.
-
Table 1 — the first three alkenes Name Molecular formula Structural formula ethene C₂H₄ CH₂=CH₂ propene C₃H₆ CH₃CH=CH₂ butene to be found CH₃CH₂CH=CH₂ (a)
(1)Complete
Complete Table 1 by giving the molecular formula of butene.
Table 1 — the first three alkenes Name Molecular formula Structural formula ethene C₂H₄ CH₂=CH₂ propene C₃H₆ CH₃CH=CH₂ butene to be found CH₃CH₂CH=CH₂ (b)
(2)Give
Give the number of hydrogen atoms attached to each carbon of the double bond in propene, using Table 1.
Table 1 — the first three alkenes Name Molecular formula Structural formula ethene C₂H₄ CH₂=CH₂ propene C₃H₆ CH₃CH=CH₂ butene to be found CH₃CH₂CH=CH₂ (c)
(3)Explain
Explain why every compound in Table 1 is described as unsaturated.
Table 1 — the first three alkenes Name Molecular formula Structural formula ethene C₂H₄ CH₂=CH₂ propene C₃H₆ CH₃CH=CH₂ butene to be found CH₃CH₂CH=CH₂ (d)
(3)Suggest
The butene in Table 1 has the double bond at the end of the chain. Suggest why more than one compound could be called butene.
Table 1 — the first three alkenes Name Molecular formula Structural formula ethene C₂H₄ CH₂=CH₂ propene C₃H₆ CH₃CH=CH₂ butene to be found CH₃CH₂CH=CH₂ (Total for Question 1 = 9 marks)
-
(1)Which
Which is the functional group of the alkenes?
Group A –OH B C=C C –COOH D C–C (Total for Question 2 = 1 mark)
-
(1)Give
Give the general formula for the alkenes.
(Total for Question 3 = 1 mark)
-
(1)State what is meant by
State what is meant by an unsaturated hydrocarbon.
(Total for Question 4 = 1 mark)
-
(2)Determine
Determine the molecular formula of the alkene with six carbon atoms.
(Total for Question 5 = 2 marks)
-
(3)Explain
Explain why an alkene has two fewer hydrogen atoms than the alkane with the same number of carbons.
(Total for Question 6 = 3 marks)
-
(2)Compare
Compare the structures of ethane and ethene.
(Total for Question 7 = 2 marks)
-
(3)Suggest
Suggest why there is no alkene with only one carbon atom.
Table 1 — the first three alkenes Name Molecular formula Structural formula ethene C₂H₄ CH₂=CH₂ propene C₃H₆ CH₃CH=CH₂ butene to be found CH₃CH₂CH=CH₂ (Total for Question 8 = 3 marks)
-
(4)Explain
But-1-ene and but-2-ene both have the molecular formula C₄H₈. Explain why they are different compounds.
(Total for Question 9 = 4 marks)
Have them marked, then defend the answer
Practice tells you the mark; teaching it back tells you whether you understand it. On Incandio a topic counts as mastered only once you have taught it and defended it.
- Mark these questions — 12 questions, marked on Incandio against the authored scheme, with the mistake you actually made named.
- Teach it — explain alkenes to Ember, an AI pupil who does not have it yet and asks the awkward question.
- Defend it — argue it against Emil Erlenmeyer over three rounds, marked against descriptors you can read first.
Completely free. No subscriptions, no paywalls, no account needed to start.
Back to the lesson
- Alkenes — Two hydrogens missing, one double bond gained — and a family that is far more useful for it.
- All of Incandio Chemistry · Incandio Exam Practice