Free Chemistry of Hydrocarbons MCQs with Answers
1,091 Chemistry of Hydrocarbons MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Hydrocarbons are studied through the structures and reactions of alkanes, alkenes, alkynes and aromatic compounds. Coverage includes free radical substitution in alkanes, electrophilic addition to carbon-carbon multiple bonds, benzene substitution, aromatic stability and the difference between addition reactions of alkenes and substitution reactions of benzene.
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Read the Chemistry of Hydrocarbons notesFree MDCAT chapter notes with key terms1,091 questions · page 21 of 55
- A. Aluminium triethyl (C2H5)3 only
- B. Titatinum tetrachloride (TiCI4) only
- C. TiCl4 + AlCl3
- D. TiCl4 + Al(C2H5)3
Explanation: In the process of addition polymerization of ethene to form polythene, the catalyst combination of titanium tetrachloride and aluminium…
Correct answer: TiCl4 + Al(C2H5)3- A. They are electron-donating groups
- B. They increase reactivity of mono- substituted benzene ring
- C. They have all lone pair at the central atom of molecules except alkyl group
- D. Halogeno-substituted benzene is less reactive than benzene
Explanation: o- and p- directing groups are known for their ability to direct incoming substituents to the ortho and para positions on a benzene ring.
Correct answer: They have all lone pair at the central atom of molecules except alkyl group- A. Resonance energy
- B. Resonance method
- C. Crystal field theory
- D. Atomic orbital treatment
Explanation: Crystal field theory primarily deals with the electronic structure and bonding in transition metal complexes, not aromatic hydrocarbons…
Correct answer: Crystal field theory- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: When toluene undergoes oxidation with acidified KMnO4, it produces benzoic acid along with water.
Correct answer: Option C- A. Sodium acetate
- B. Sodium Succinate
- C. Sodium oxalate
- D. Potassium maleate
Explanation: Potassium maleate, a salt of maleic acid, is the specific salt used in Kolbe's electrolytic method to prepare ethyne.
Correct answer: Potassium maleate- A. Glyoxal
- B. Glycol
- C. Acetic acid
- D. Oxalic acid
Explanation: Ethyne on oxidation with strong alkaline KMnO4, gives glyoxal which is further oxidized to produce oxalic acid as the ultimate product.
Correct answer: Oxalic acid- A. 1
- B. 4
- C. 2
- D. 3
Explanation: The preparation of acetaldehyde from ethyne (acetylene) and water in the presence of HgSO4/H2SO4 at 75°C involves two steps.
Correct answer: 2- A. White
- B. Reddish brown
- C. Yellow
- D. Violet
Explanation: When ethyne reacts with ammonical Cu2Cl2 solution, dicopper acetylide is formed, which appears reddish brown in color.
Correct answer: Reddish brown- A. Vinyl acetylene
- B. Di-vinyl acetylene
- C. Neoprene
- D. benzene
Explanation: When acetylene is passed under pressure over an organo-nickel catalyst at 70°C, it undergoes a trimerization reaction where three…
Correct answer: benzene- A. CH3CHO, CH3COOH
- B. CH3COCH3, CH3COOH
- C. CH3CH2OH, CH3CHO
- D. CH3CHO, CH3CH2OH
Explanation: The correct answer is Option A:CH3CHO, CH3COOH. This is because during the oxidation of ethanol, it first forms acetaldehyde (CH3CHO) and…
Correct answer: CH3CHO, CH3COOH- A. In it each carbon atom has sp2-orbital hybridization
- B. It is cyclic hexagonal planar structure
- C. It has diffused or decolonized electron cloud
- D. It has 6 sigma bonds and 6 pi electrons
Explanation: The correct answer is Option D. While the statement in Option D correctly mentions the 6 pi electrons in benzene, it incorrectly states…
Correct answer: It has 6 sigma bonds and 6 pi electrons- A. Alicyclic hydrocarbons
- B. Aromatic hydrocarbon
- C. Aliphatic saturated hydrocarbon
- D. Aliphatic unsaturated hydrocarbon
Explanation: Cyclohexane is classified as an alicyclic hydrocarbon due to its closed-ring structure.
Correct answer: Alicyclic hydrocarbons- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The correct structural formula for 4-Ethyl-3,4-dimethylheptane involves identifying the longest carbon chain (heptane) and placing the…
Correct answer: Option A- A. Alkane
- B. Alkene
- C. Benzene
- D. Alkyne
Explanation: Alkenes are the most reactive hydrocarbons in terms of electrophilic addition because the double bond allows them to attract electrophiles…
Correct answer: Alkene- A. Reaction with hydrogen (hydrogenation)
- B. Reaction with HX (hydrohalogenation)
- C. Reaction with H20 (hydration)
- D. All of these
Explanation: Ethene, also known as ethylene, is an alkene with a double bond between two carbon atoms.
Correct answer: All of these- A. Hydrogenation
- B. Hydrohalogenation
- C. Hydration
- D. All of these
Explanation: Alkynes are capable of undergoing addition reactions due to the presence of a triple bond with loosely held pi-electrons.
Correct answer: All of these- A. Cyclohexane
- B. Benzene
- C. Ethyne
- D. Pentene
Explanation: Cyclohexane is the correct answer as it is a ring chain compound that does not contain alternate single and double bonds, making it an…
Correct answer: Cyclohexane- A. Ethene
- B. Propene
- C. Ethane
- D. Ethyne
Explanation: Ethene, also known as ethylene, is the correct answer as it is a gaseous plant hormone that plays a vital role in inducing the ripening…
Correct answer: Ethene- A. Alkanes
- B. Alkynes
- C. Carbonyl
- D. Alkenes
Explanation: Alkenes are the correct answer because they specifically contain carbon-carbon double bonds, distinguishing them from alkanes, alkynes…
Correct answer: Alkenes- A. Hydration
- B. Sulphonation
- C. Hydrogenation
- D. Dehydrogenation
Explanation: Hydrogenation is the correct answer because it is specifically used in the preparation of vegetable oil and helps in prolonging the shelf…
Correct answer: Hydrogenation