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 25 of 55
481. The hydrogenation Reactions of alkanes at 200°C-300°C temperature, takes place in the presence of
- A. Platinum
- B. Copper
- C. Nickel
- D. Chromium
Explanation: In the hydrogenation reactions of alkanes at high temperatures, nickel serves as an effective catalyst due to its capability to adsorb…
Correct answer: Nickel- A. Alkynes
- B. Alkenes
- C. Alkanes
- D. All of these
Explanation: The Sabatier-Senderens reaction is used to prepare alkanes by reducing carboxylic acids.
Correct answer: Alkanes- A. Pi bonds
- B. Sigma bonds
- C. None of these
- D. Both of these
Explanation: In hydrogenation, the cleavage primarily occurs in pi bonds as hydrogen molecules are added across unsaturated hydrocarbons, forming…
Correct answer: Pi bonds- A. Pi bonds
- B. Sigma bonds
- C. None of above
- D. Both of above
Explanation: Hydrogenolysis involves the breaking of sigma bonds. These are the single covalent bonds between atoms, and when hydrogen gas adds to one…
Correct answer: Sigma bonds- A. Nickel
- B. Palladium
- C. Palladium charcoal
- D. None of these
Explanation: Palladium charcoal is commonly used as a catalyst in hydrogenolysis reactions due to its ability to adsorb and activate hydrogen gas…
Correct answer: Palladium charcoal- A. Hydrogenation
- B. Hydrolysis
- C. Hydrogenolysis
- D. Hydroxylation
Explanation: Hydrogenolysis involves the addition of hydrogen to a molecule along with the breaking of bonds, resulting in the cleavage of the…
Correct answer: Hydrogenolysis- A. Water
- B. Carbon dioxide
- C. Hydrogen
- D. None of above
Explanation: Decarboxylation of monocarboxylic acids involves the removal of a carboxyl group (-COOH) from the molecule.
Correct answer: Carbon dioxide- A. Electrolysis
- B. Photolysis
- C. None of above
- D. All of these
Explanation: Kolbe's electrolytic method involves the electrolysis of salts of carboxylic acids to produce alkanes.
Correct answer: Electrolysis- A. Reduction of Alkyl compound
- B. Reduction of aldehyde
- C. Reduction of ketones
- D. All of these
Explanation: The Clemmensen reduction is commonly used for the reduction of ketones.
Correct answer: Reduction of ketones- A. Grignard reagent
- B. Wolf-kishner reagent
- C. Clemmensen reagent
- D. None of these
Explanation: Alkyl halides react with magnesium in anhydrous ether to form alkyl magnesium halides known as Grignard reagents.
Correct answer: Grignard reagent491. In Clemmensen reduction Zn-Hg/HCl and in in Wolf kishner reduction N2H4/KOH is used to generate
- A. Hydrogen peroxide
- B. Hydrogen molecules
- C. Oxygen
- D. Nascent hydrogen
Explanation: In Clemmenson reduction, Zn-Hg/HCl and in Wolf-Kishner reduction, N2H4/KOH generate nascent (active) hydrogen.
Correct answer: Nascent hydrogen- A. Mustard gas
- B. Launching gas
- C. Phosgene gas
- D. Biogas
Explanation: Beta and beta prime dichloro ethyl sulphide is commonly known as Mustard gas.
Correct answer: Mustard gas- A. Chloroform only
- B. Carbon tetrachloride only
- C. Chloromethane and dichloromethane
- D. Mixture of a, b, and c
Explanation: The correct answer is Option D: Mixture of chloromethane, dichloromethane, and chloroform.
Correct answer: Mixture of a, b, and c- A. Alkanes
- B. Alkenes
- C. Alkynes
- D. Alkyls
Explanation: Saturated hydrocarbons have only single bonds between carbon atoms. Alkanes specifically refer to saturated hydrocarbons containing only…
Correct answer: Alkanes- A. Alkanes
- B. Alkenes and alkynes
- C. Alkynes
- D. Alkaloids
Explanation: Alkenes and alkynes are unsaturated hydrocarbons because they contain double and triple bonds, respectively, between carbon atoms.
Correct answer: Alkenes and alkynes- A. Double bond only
- B. Double and single bond
- C. Only single bond
- D. Triple bond
Explanation: Alkanes are hydrocarbons that are composed of only single bonds between carbon atoms.
Correct answer: Only single bond- A. Oxidizing agent
- B. Eliminating agent
- C. Reducing agent
- D. None of above
Explanation: Option C is correct: N2H4/KOH is used as a reducing agent in the Wolf-Kishner reduction because it helps in the reduction of carbonyl…
Correct answer: Reducing agent- A. Two
- B. Three
- C. Four
- D. Zero
Explanation: Alkenes have two fewer hydrogen atoms compared to the corresponding saturated hydrocarbons (alkanes) due to the presence of a…
Correct answer: Two- A. Paraffin
- B. Olefins
- C. A,b both
- D. None of above
Explanation: Alkenes are commonly known as Olefins because they are unsaturated hydrocarbons with at least one carbon-carbon double bond.
Correct answer: Olefins- A. Methene
- B. Ethene
- C. Propene
- D. Butene
Explanation: Ethene, also known as ethylene, is the correct answer as it is one of the simplest olefins with two carbon atoms and four hydrogen atoms.
Correct answer: Ethene