CIE iGCSE Co-Ordinated Science C11.5 Alkenes Exam Style Questions Paper 2
Question
Which substance decolorizes aqueous bromine?
▶️Answer/Explanation
Ans: C
Question
Hydrocarbon X has two carbon atoms in each molecule. It does not decolourise bromine water.
Hydrocarbon Y has three carbon atoms in each molecule. It does decolourise bromine water.
What is the difference in the number of hydrogen atoms in the molecules of X and Y?
A 0 B 1 C 2 D 4
▶️Answer/Explanation
Ans : A
Question
Which statements about ethene and but-1-ene are correct?
1 Only ethene reacts with bromine water.
2 They are both formed by cracking alkanes.
3 They both react with steam to form alcohols.
4 They have different general formulae.
A 1 and 2 B 1 and 4 C 2 and 3 D 3 and 4
▶️Answer/Explanation
Ans :C
Question
Which substances can be produced by cracking?
A. alkanes only
B. alkenes only
C. alkenes and hydrogen only
D. alkanes, alkenes and hydrogen
▶️Answer/Explanation
Answer: D. alkanes, alkenes and hydrogen
Explanation: Cracking is a process that breaks down larger hydrocarbon molecules into smaller ones, producing alkanes, alkenes, and hydrogen as byproducts.