CIE iGCSE Co-Ordinated Science C11.4 Alkanes Exam Style Questions Paper 1
▶️ Answer/Explanation
Alkanes are saturated hydrocarbons that contain only single covalent bonds between their carbon atoms. They are generally unreactive and do not react with aqueous bromine (unlike alkenes, which decolorise bromine water). Alkanes also do not form polymers because polymerisation requires double bonds. Therefore, option B is the correct statement.
✅ Answer: (B)
✅ Answer: (B)
▶️ Answer/Explanation
Alkanes are saturated hydrocarbons containing only single carbon–carbon bonds.
Because they are saturated, they do not decolourise aqueous bromine and are not used to make addition polymers — those properties belong to alkenes.
Alkanes undergo combustion easily, which is why they are widely used as fuels.
✅ Answer: (D)
Because they are saturated, they do not decolourise aqueous bromine and are not used to make addition polymers — those properties belong to alkenes.
Alkanes undergo combustion easily, which is why they are widely used as fuels.
✅ Answer: (D)
Question
Which statement about alkanes is correct?
(A) They rapidly decolourise aqueous bromine.
(B) They are unsaturated hydrocarbons.
(C) They are used to make polymers.
(D) They can be used as fuels.
▶️Answer/Explanation
Ans: D
Question
Which row describes properties of alkenes?
| structure of molecules | products of complete combustion | |
|---|---|---|
| A | contain only carbon and hydrogen | CO₂ and H₂O |
| B | contain only carbon and hydrogen | CO and H₂O |
| C | contain only single bonds | CO and H₂O |
| D | contain only single bonds | CO₂ and H₂O |
▶️Answer/Explanation
Answer: A) contain only carbon and hydrogen, CO₂ and H₂O
Explanation: Alkenes are hydrocarbons containing carbon-carbon double bonds. When they undergo complete combustion, they produce carbon dioxide (CO₂) and water (H₂O).