Alkene MCQs

21. Alkenes can be distinguished from alkanes by using:

• A) Bromine water
• B) Sodium chloride
• C) Silver nitrate
• D) Water
• Answer: A

22. Which of the following is a terminal alkene?

• A) 1-Butene
• B) 2-Butene
• C) Cyclohexene
• D) Ethene
• Answer: A

23. Which of the following alkenes has cis and trans isomers?

• A) Ethene
• B) Propene
• C) 1-Butene
• D) 2-Butene
• Answer: D

24. In the IUPAC name, the position of the double bond in alkenes is indicated by:

• A) The position of the longest chain
• B) The position of the first carbon in the double bond
• C) The number of substituents
• D) The total number of carbon atoms
• Answer: B

25. What happens when bromine water is added to an alkene?

• A) No reaction occurs
• B) The solution turns brown
• C) The solution turns colorless
• D) The solution forms a precipitate
• Answer: C

26. The addition of HBr to an alkene results in the formation of:

• A) An alcohol
• B) A haloalkane
• C) A ketone
• D) An ester
• Answer: B

27. Alkenes undergo electrophilic addition reactions because:

• A) They contain π-bonds
• B) They have high bond dissociation energy
• C) They are saturated
• D) They contain only σ-bonds
• Answer: A

28. What is the major product of the hydration of an alkene?

• A) Alkane
• B) Alkyl halide
• C) Alcohol
• D) Ether
• Answer: C

29. What is the bond angle around the double bond in an alkene?

• A) 90°
• B) 120°
• C) 109.5°
• D) 180°
• Answer: B

30. The reaction of alkenes with ozone is called:

• A) Hydroboration
• B) Oxidation
• C) Ozonolysis
• D) Dehydrohalogenation
• Answer: C