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 54 of 55
- A. 1-chloro 1-butanol
- B. 2-chloro 1-butanol
- C. Both (A) and (B)
- D. None of the above
Explanation: When hypochlorous acid (HClO) reacts with 1-butene, the main product formed is 1-chloro-1-butane.
Correct answer: None of the above- A. 2-Pentanone
- B. pentanol
- C. 3-Pentanone and Ethanal
- D. 7-Heptanone
Explanation: When 3-Ethyl-2-Pentene undergoes ozonolysis, it reacts with ozone (O3) to form two pentanone molecules.
Correct answer: 2-Pentanone- A. cis-2-butene
- B. Isobutylene
- C. trans-2-butene
- D. 1-butene
Explanation: trans-2-butene is the most stable option among the given choices because it has a straight-chain configuration with no steric…
Correct answer: trans-2-butene- A. CH4
- B. C2H2
- C. C2H4
- D. C2H6
Explanation: Metallic carbide/Calcium Carbide: CaC2 Calcium carbide on hydration gives acetylene.
Correct answer: C2H2- A. C2H6
- B. C2H4
- C. C2H2
- D. C6H6
Explanation: Only alkynes can perform this reaction. 2[Cu(NH)3]OH + HC≡CH → Cu−C≡C−Cu + 4NH3 + 2H2O copper acetylide Red ppt.
Correct answer: C2H2- A. Br2 in organic solvent
- B. Baeyer's reagent
- C. Phenyl Hydrazine
- D. Tollen's reagent
Explanation: The correct answer is Tollen's reagent. Ethene does not react with Tollen's reagent, whereas Ethyne reacts with it to form a white…
Correct answer: Tollen's reagent- A. CnH2n+2
- B. CnH2n
- C. CnH2n-2
- D. Both CnH2n and CnH2n-2
Explanation: Alkynes on hydration in the presence of H2SO4 and HgSO4 yield carbonyl compounds through enolAll alkynes except ethyne give ketones while…
Correct answer: CnH2n-2- A. Toluene
- B. 2-butyne
- C. 1-butyne
- D. 2-butene
Explanation: EToluene, which is a hydrocarbon, does not typically undergo acid-base reactions.
Correct answer: Toluene- A. Vinyl chloride
- B. Ethyl chloride
- C. 1,2 - dichloroethane
- D. 1,1 - dichloroethane
Explanation: When excess hydrochloric acid (HCl) is added to acetylene (C2H2), the product formed is 1,2 - dichloroethane (C2H4Cl2).
Correct answer: 1,2 - dichloroethane- A. m-directing
- B. o-directing
- C. o -& p -directing & deactivating
- D. o -& p -directing & activating
Explanation: Chlorine has a lone pair, so it can donate electrons to the benzene ring.
Correct answer: o -& p -directing & deactivating- A. C2H5
- B. SO3H
- C. NH2
- D. CH3
Explanation: order of activating group (NH2, NHR, NHCOCH3, OCH3,CH3,C2H5(and deactivating group (NO2, CN, CHO, COR, COOH, COOR, SO3H)to increase and…
Correct answer: SO3H- A. A cyclic compounds
- B. Ali cyclic compounds
- C. Hetro cyclic compounds
- D. Aromatic compounds
Explanation: Aromatic compounds are a class of cyclic organic compounds that contain one or more rings with a special stability due to the…
Correct answer: Aromatic compounds- A. R
- B. OH
- C. COR
- D. NH2
Explanation: The acyl group (COR) is not ortho para directing and activating. It is a deactivating group due to the presence of the carbonyl group…
Correct answer: COR- A. -OH
- B. -OR
- C. -NH2
- D. -CN
Explanation: -CN (Cyano group) is a deactivating group. It withdraws electron density from the ring through the inductive effect, reducing the…
Correct answer: -CN- A. of its cyclic nature
- B. of having three double bonds
- C. of aromatic character
- D. of delocalization of electrons
Explanation: The correct answer is that benzene undergoes substitution reactions more easily due to the delocalization of electrons.
Correct answer: of delocalization of electrons- A. An aromatic compound cannot be completely converted into CO2 and other products during burning
- B. The available amount of oxygen present in the air is not sufficient to completely burn the available compound
- C. Aromatic compounds produce compounds on burning that are of black color
- D. None of the above
Explanation: Aromatic compounds produce a smoky flame when burned due to their high carbon content.
Correct answer: The available amount of oxygen present in the air is not sufficient to completely burn the available compound- A. slower rate
- B. faster rate
- C. same rate
- D. depends on the conditions
Explanation: Compared to benzene, nitration of toluene occurs at a faster rate due to the presence of the methyl group (-CH3), which is an…
Correct answer: faster rate- A. PVC
- B. Benzene
- C. Toluene
- D. Teflon
Explanation: Benzene is formed by the cyclic trimerization of three ethyne (acetylene) molecules in a chemical process that rearranges the atoms into a…
Correct answer: Benzene- A. They have ring structure of carbon atoms.
- B. They have a relatively high percentage of hydrogen atoms.
- C. They have a relatively high percentage of carbon atoms.
- D. They resist reactions with air/oxygen.
Explanation: The aromatic compound displays aromaticity. They burn with a strong sooty yellow flame.
Correct answer: They have a relatively high percentage of carbon atoms.- A. -R
- B. -COR
- C. -NH2
- D. NR2
Explanation: Ortho and para directing grps release electrons to the benzene ring increasing the chemical reactivity of the benzene ring towards…
Correct answer: -COR