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 43 of 55
- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The introduction of an alkyl group (an alkyl substitution) into benzene takes place through a Friedel-Crafts alkylation reaction.
Correct answer: Option B- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: When propene (CH3-CH=CH2) reacts with hydrogen bromide (HBr), it undergoes an addition reaction to form 2-bromopropane.
Correct answer: Option D- A. H2SO4
- B. AlCl3
- C. HNO3
- D. HCI
Explanation: Any halogen in its standard state is not a strong electrophile to attack the electron cloud on the benzene ring and react with it.
Correct answer: AlCl3- A. Carboxylic acid
- B. Aldehyde
- C. Ketone
- D. Alcohol
- E. All
Explanation: The catalytic oxidation of alkanes can result in the formation of carboxylic acids, aldehydes, ketones, and alcohols
Correct answer: All- A. Mustard gas
- B. Launching gas
- C. Phosgene gas
- D. Bio gas
Explanation: Beta and beta prime dichloro ethyl sulphide is commonly known as Mustard gas.
Correct answer: Mustard gas- A. Numbering starts from functional group which is double bond in this case
- B. Single bond
- C. Triple bond
- D. Hydrogen bond
Explanation: Numbering starts from functional group which is double bond in this case
Correct answer: Numbering starts from functional group which is double bond in this case- A. 120kJ/mole
- B. 130 kJ/mole
- C. 125kJ/ mole
- D. 150 kJ/mole
Explanation: Factual statement that needs to be learnt
Correct answer: 120kJ/mole- A. Aluminum
- B. Nickel
- C. Cupper
- D. Sodium
Explanation: Raney nickel is a form of nickel used as catalyst
Correct answer: Nickel- A. 200°C and 100 atm
- B. 500°C and 200 atm
- C. 400°C and 100 atm
- D. 400°C and 200 atm
Explanation: Option C provides the most suitable conditions for the polymerization of ethene to polyethylene: Temperature of 400°C: This temperature is…
Correct answer: 400°C and 100 atm- A. Ethene
- B. Ethane
- C. Propane
- D. Peopene
Explanation: Ethene is not colorless. It is a colorless gas with a slightly sweet odor.
Correct answer: Ethene- A. Ice-cream
- B. Chewing gum
- C. Detergents
- D. Prefumes
Explanation: Vanillin is a popular flavoring agent used in various food products. Among the given options, ice-cream is the product that commonly…
Correct answer: Ice-cream- A. CH 2
- B. COOH
- C. C6H6
- D. Ç6H12011
Explanation: Benzene is an organic compound composed of six carbon atoms (C6) arranged in a hexagonal ring, with each carbon atom bonded to one…
Correct answer: C6H6- A. C6H6 + CH3CI
- B. C6H6
- C. C6H5C2H5
- D. C6H5CI & CH3Cl
Explanation: Toluene can be prepared by the Friedel-Crafts alkylation of benzene with methyl chloride (CH3Cl) in the presence of anhydrous aluminum…
Correct answer: C6H6 + CH3CI- A. - NO2
- B. - NH2
- C. - OH
- D. - COOH
Explanation: The nitro group (NO2) is electron-withdrawing because it has a high electronegativity.
Correct answer: - NO2- A. -NH2
- B. -CHO
- C. -OH
- D. All of these
Explanation: Option B is correct.The -CHO group deactivates the benzene ring. Electron-withdrawing groups, like the -CHO group, withdraw electrons from…
Correct answer: -CHO- A. Carboxylic acid
- B. Aldehyde
- C. Ketone
- D. Alcohol and/or carbonyl compounds
Explanation: Catalytic oxidation of alkanes results in the formation of alcohols and/or carbonyl compounds.
Correct answer: Alcohol and/or carbonyl compounds- A. HCl bond is too strong to be broken homolytically
- B. Cl atom is not reactive enough to add on to a double bond.
- C. Cl combines with H to give back HCl
- D. HCl is a reducing agent
Explanation: Peroxides can act as radical initiators and generate highly reactive chlorine radicals (Cl•) from HCl.
Correct answer: HCl bond is too strong to be broken homolytically- A. Intensity of UV light
- B. Concentration of X2 used
- C. Temperature
- D. All of these
Explanation: The extent of halogenation depends on all these factors. CH4+X2 → CH3X+HXCH4+2X2→ CH2X2 +2HXCH4+3X2→ CHX3+3HXCH4+4X2→ CX4 +4HX
Correct answer: All of these- A. It takes place in the presence of less polar solvent (like alcohol)
- B. It takes place at high temperature
- C. It requires strong nueleophile (base)
- D. It takes place at low temperature
Explanation: Option D is correct. β-elimination reactions are generally favored at higher temperatures.
Correct answer: It takes place at low temperature- A. H2C = CH2
- B. R - CH = CH - R
- C. R1R2C = CR3R4
- D. R1R2C = CHR4
Explanation: When a symmetrical alkene like R1R2C=CR3R4 is treated with hot concentrated KMnO4, it undergoes oxidative cleavage to produce two moles of…
Correct answer: R1R2C = CR3R4