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 19 of 55
- A. Exothermic process
- B. Isothermic process
- C. Endothermic process
- D. Both A and B
Explanation: This reaction is the hydrogenation of benzene. It involves breaking three pi bonds and forming six new and stronger C-H sigma bonds.
Correct answer: Exothermic process- A. Addition reaction
- B. Substitution reaction
- C. Elimination reaction
- D. Polymerization
Explanation: In this reaction, hydrogen atoms are added across the double bonds of the benzene ring, breaking the pi bonds to form a saturated…
Correct answer: Addition reaction- A. 1-bromopropane
- B. 2-bromopropane
- C. propyl bromide
- D. 3-bromopropene
Explanation: Propene reacts with HBr by Markovnikov's rule, so hydrogen adds to the carbon with more hydrogens, forming 2-bromopropane as the major…
Correct answer: 2-bromopropane- A. Hydrolysis of phenyl magnesium iodide - phenol
- B. γ-Isomer BHC - Lindane
- C. (4n+2)π rule - Aromaticity
- D. Trimerization of propyne - Mesitylene
Explanation: The correct answer is Option A: The hydrolysis of phenyl magnesium iodide does not produce phenol it's yield benzene making this option…
Correct answer: Hydrolysis of phenyl magnesium iodide - phenol- A. 135 lit
- B. 35 lit.
- C. 175 lit
- D. 205 lit
Explanation: For the complete combustion of ethane (C2H6), the balanced chemical equation is: C2H6 + 3.5O2 → 2CO2 + 3H2O.
Correct answer: 175 lit366. The treatment of CH3OH with CH3MgI releases 1.04 ml of a gas at STP. The mass of CH3OH added is:
- A. 1.485 mg
- B. 2.98 mg
- C. 3.71 mg
- D. 4.47 mg
Explanation: To solve this problem, first calculate the number of moles of gas released at STP using the ideal gas law equation.
Correct answer: 1.485 mg- A. isobutyl benzene
- B. tert-butyl benzene
- C. n-butyl benzene
- D. sec-butyl benzene
Explanation: When benzene reacts with isobutyl chloride in the presence of AlCl3, tert-butyl benzene is formed.
Correct answer: tert-butyl benzene- A. 3
- B. 5
- C. 2
- D. 4
Explanation: When a compound containing carbon, hydrogen, and oxygen atoms reacts with CH3MgI to produce a gas with a volume of 89.6 liters under STP…
Correct answer: 4- A. 1-Butene
- B. 2-Methylpropene
- C. 2,3-Dimethyl-2-butene
- D. 2,3-Dimethyl-1-butene
Explanation: The reactivity of alkenes in catalytic hydrogenation is influenced by steric hindrance, with alkenes having less hindrance reacting…
Correct answer: 1-Butene- A. Cl2 → 2Cl
- B. CH4 + Cl → CH3 + HCl
- C. Cl° + Cl° → Cl2
- D. CH3 + Cl2 → CH3Cl + Cl°
Explanation: The termination step in the chlorination of methane involves the combination of two chlorine radicals to form molecular chlorine, thereby…
Correct answer: Cl° + Cl° → Cl2- A. Tertiary > Secondary > Primary
- B. Primary > Secondary > Tertiary
- C. Secondary < Primary < Tertiary
- D. Tertiary < Secondary < Primary
Explanation: The ease of dehydration of alcohols to produce alkenes is directly related to the number of beta-carbon atoms in the alcohol.
Correct answer: Tertiary > Secondary > Primary- A. Addition
- B. Neutralization
- C. Dehydration
- D. Oxidation
Explanation: When ethene reacts with hydrogen, an addition reaction occurs where the unsaturated ethene molecule becomes saturated with the addition of…
Correct answer: Addition- A. 1-Pentene
- B. Pentane
- C. 2-Methyl-1-butene
- D. Both "A" and "C"
Explanation: Correct! Bromine water is decolorized by unsaturated hydrocarbons like 1-Pentene and 2-Methyl-1-butene through addition reactions with…
Correct answer: Both "A" and "C"- A. Diols
- B. Vicinal diols
- C. Geminal diols
- D. Mono-ols
Explanation: When alkenes undergo hydroxylation, the correct product produced is vicinal diols.
Correct answer: Vicinal diols- A. Halogenation
- B. Hydrogenation
- C. Hydroxylation
- D. Dehydrogenation
Explanation: Vegetable ghee is prepared from vegetable oil which is a tri-ester of unsaturated fatty acids with glycerol.
Correct answer: Hydrogenation- A. CH3CH=CH2 + HCl →
- B. CH3CH2CH=CH2+ HI→
- C. CH3CH=CH2 + HBr→
- D. CH3CH=CHCH3 + HBr→
Explanation: Markownikov's rule is generally followed in addition reactions, where the hydrogen atom attaches to the carbon with more hydrogen atoms.
Correct answer: CH3CH=CHCH3 + HBr→- A. Cl+
- B. Cl-1
- C. H+
- D. H∘
- E. Cl-
Explanation: When HCl is added to an alkene, the first species to add is the proton (H+), which adds to the carbon of the double bond that has the most…
Correct answer: H+- A. Reduction
- B. Oxidation
- C. Detection of double bond
- D. Detection of glucose
Explanation: Baeyer's reagent, also known as potassium permanganate, is primarily used in the laboratory to detect the presence of double bonds…
Correct answer: Detection of double bond- A. Toluene
- B. o-Xylene
- C. m-Xylene
- D. Benzoic acid
Explanation: When CH3Cl reacts with benzene in the presence of AlCl3, it forms toluene.
Correct answer: Benzoic acid- A. Addition reaction
- B. Substitution reaction
- C. Elimination reaction
- D. Polymerization
Explanation: The given reaction is an example of an addition reaction because it involves the combination of reactants without the loss of any atom or…
Correct answer: Addition reaction