Free Alkenes MCQs with Answers
89 Alkenes MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alkenes are unsaturated hydrocarbons containing a carbon-carbon double bond with sigma and pi components and restricted rotation. Their reactions include electrophilic addition of hydrogen, halogens, hydrogen halides and water, with Markovnikov orientation, oxidation, combustion and polymerisation, while their preparation commonly involves elimination from alkyl halides or alcohols.
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- A. Alkanes
- B. Alkenes
- C. Alkynes
- D. All of the above options are correct
Explanation: Geometric Isomerism results most commonly from C=C. The important property which introduces the feature is the inability of the Carbon…
Correct answer: Alkenes- A. Alcohol
- B. Ethers
- C. Alkynes
- D. Alkenes
Explanation: Geometric Isomerism is commonly observed in Carbon-Carbon double bonds. Carbon-carbon double bonded compounds have restricted rotation.
Correct answer: Alkenes- A. 1-chloropropane
- B. 2-chloropropane
- C. 3-chloropropane
- D. None pf the above
Explanation: HCl reacts with propene in an electrophilic addition reaction. According to Markovnikov's rule, the H (of HCl) bonds to the carbon which…
Correct answer: 2-chloropropane- A. Decomposition
- B. Dehydration
- C. Dehydroxylation
- D. Dehalogenation
Explanation: Ethene is prepared from alcohol by dehydration. Dehydration is the removal of water from a compound.
Correct answer: Dehydration- A. Hydrohalogenation of alkenes
- B. Dehydration of alkenes
- C. Hydration of alkenes
- D. Hydroxylation of alkenes
Explanation: he method that is used on an industrial scale for the production of alcohol from alkene is hydration of alkenes.
Correct answer: Hydration of alkenes- A. Nickel
- B. Gold
- C. Palladium
- D. Raney Nickel
Explanation: OPTION A: Hydrogenation of alkenes does not occur in the presence of simple nickel because it does not have the necessary activity and…
Correct answer: Raney Nickel- A. Ethylene glycol
- B. Ethylene epoxide
- C. Methylene oxide
- D. Both Options A and B are correct
Explanation: Alkenes are capable of reacting with oxygen in the presence of elemental silver to form a series of cyclic ethers called epoxides.
Correct answer: Ethylene epoxide- A. Trans-isomers
- B. Alkanes
- C. Cis-isomers
- D. Positional isomers
Explanation: Only in cis-trans isomers, there is a double bond between the carbon atoms having bulky groups on either side.
Correct answer: Trans-isomers- A. -ene
- B. -ylene
- C. -yne
- D. -eylene
Explanation: OPTION A: In the IUPAC system of alkenes, the suffix -ane of the corresponding alkane is replaced by the suffix -ene.
Correct answer: -ylene- A. Dehydration
- B. Ozonolysis
- C. Markovnikov's addition
- D. Oxidation with KMnO4
Explanation: OPTION A: Dehydration reactions can be defined as chemical reactions in which a water molecule is eliminated from the reactant molecule.
Correct answer: Ozonolysis- A. Dehydration
- B. Hydroxylation
- C. Hydration
- D. Luca's test
Explanation: When ethene is subjected to 'hydroxylation' in the presence of cold and dilute alkaline potassium permanganate solution, the addition of…
Correct answer: Hydroxylation- A. -ene
- B. -ane
- C. -yne
- D. -ylene
Explanation: -ene is IUPAC suffix -ane is for alkanes -yne is for alkynes
Correct answer: -ene- A. Direct addition
- B. Markovnikov's addition
- C. Anti Markovnikov's addition
- D. Dehydration
Explanation: Since the alkene and the reagent (HBr) are both unsymmetrical markovnikov's rule will be followed.
Correct answer: Markovnikov's addition- A. Potassium formate
- B. Potassium succinate
- C. Potassium acetate
- D. Potassium fumarate
Explanation: Option B is correct since Kolbe's electrolysis of potassium succinate gives CO2 and C2H4.
Correct answer: Potassium succinate- A. HBr.
- B. HCL.
- C. Br2..
- D. None of these.
Explanation: When ethene reacts with bromine, the pi bond between the two carbon atoms is broken and the bromine molecule is added across the double…
Correct answer: Br2..- A. Br2/H2O.
- B. Dilute alkaline KMnO4.
- C. ZnCl2/HCl.
- D. Br2/CCl4.
Explanation: Baeyer's reagent is a solution of potassium permanganate (KMnO4) in sodium hydroxide (NaOH) used to test for the presence of unsaturation…
Correct answer: Dilute alkaline KMnO4.- A. HCl
- B. H2SO4/H2O
- C. HBr
- D. All of these options are correct
Explanation: Option C is correct since Markovnikov's rule states that with the addition of a protic acid HX to an asymmetric alkene, the acid hydrogen…
Correct answer: HBr- A. Polyvinyl polymer
- B. Polyvinyl Acetylene
- C. Neoprene
- D. Chloroprene
Explanation: When vinyl acetylene (also known as 1-butyne) reacts with HCl (hydrochloric acid), it undergoes a chemical reaction known as an addition…
Correct answer: Chloroprene- A. Dilute KMnO4
- B. Acidified K2Cr2O7
- C. Acidified CuCl2
- D. Pyridine
Explanation: Alkenes are readily oxidised by cold, dilute, aqueous solution of potassium permanganate (Baeyer's reagent) to give vicinal glycols.
Correct answer: Dilute KMnO4- A. Alkanes
- B. Alkynes
- C. Carbonyl
- D. Alkenes
Explanation: The functional group of alkenes is the presence of a double bond between two carbon atoms.
Correct answer: Alkenes