Free Alkanes MCQs with Answers
127 Alkanes MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Alkanes are saturated hydrocarbons containing only carbon-carbon and carbon-hydrogen single bonds, with the general formula CnH2n+2 for open chains. Their structure, isomerism, IUPAC nomenclature, physical properties, combustion, free-radical halogenation and conformations are covered, including the difference between substitution in alkanes and addition in unsaturated hydrocarbons.
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127 questions · page 4 of 7
- A. CnH2n+1
- B. CnH2n
- C. CnH2n-1
- D. CnH2n+2
Explanation: The correct answer is Option D: CnH2n+2. This formula is the general formula for alkanes, where 'n' represents the number of carbon atoms…
Correct answer: CnH2n+2- A. Ethane
- B. Ethyne
- C. Ethyl benzene
- D. Ethene
Explanation: Option A is correct as Alkanes are generally unreactive towards oxidizing reagents.
Correct answer: Ethane- A. Carbon, carbon monoxide and hydrogen
- B. Carbon and oxygen
- C. Carbon monoxide and hydrogen
- D. Carbon and carbon monoxide
Explanation: a) Carbon, carbon monoxide, and hydrogen:During the incomplete combustion of a hydrocarbon, if there is not enough oxygen available, the…
Correct answer: Carbon, carbon monoxide and hydrogen- A. Ethene
- B. Ethane
- C. Ethyne
- D. Benzene
Explanation: The explanation for this question will be added soon.
Correct answer: Ethane- A. C2H4
- B. C2H2
- C. C2H6
- D. C2H2Br
Explanation: Higher the s− character means that the Bonded pair electrons are held more closely, ensuring a smaller Bond length and a stronger bond.So…
Correct answer: C2H6- A. 1-Ethyl-2, 4-dimethlycyclohexane
- B. 2-Ethyl-1,4-dimethylcyclohexene
- C. 2-Ethyl-1, 1-dimethylcyclohexane
- D. 4-Ethyl-1, 2-dimethylcyclohexane
Explanation: The IUPAC name of the compound is 1-ethyl-2,4-dimethylcyclohexane. The parent compound is cyclohexane.
Correct answer: 1-Ethyl-2, 4-dimethlycyclohexane- A. C3 - C5 alkanes
- B. C15 - C20 alkanes
- C. C11 - C15 alkanes
- D. C7 - C9 alkanes
Explanation: C7-C9 alkanes: This range of alkanes is the ideal range for use in gasoline.
Correct answer: C7 - C9 alkanes- A. Methane
- B. Ethane
- C. Butane
- D. Nitrogen
Explanation: Natural gas has Methane and ethane contributing to large portions with Methane being 90%, approximately, and ethane, up to 5%.
Correct answer: Butane- A. CnH2n=2
- B. CnH2n
- C. CnH2n-1
- D. CnCH2n-2
Explanation: Option B shows the general formula of cycloalkane, n Is number of carbon is ring
Correct answer: CnH2n- A. CnH2n+2
- B. CnH2n
- C. CnH2n - 1
- D. CnH2n - 2
Explanation: It is because cycloalkane has the same generic formula as the alkenes which is CnH2n.
Correct answer: CnH2n- A. 2, 3 - tetramethyl butane
- B. 2, 2, 3, 3 - tetramethyl pentane
- C. 3, 3, 4, 4 - tetramethyl butane
- D. 3, 4 - bis (dimethyl butane)
Explanation: The longest carbon chain in the compound above is of five carbons as shown in the figure below, hence the correct option must have a…
Correct answer: 2, 2, 3, 3 - tetramethyl pentane- A. Isobutane
- B. Pentane
- C. Neo- pentane
- D. Isopentane
Explanation: Option C: Neo-pentane (CH3-C(CH3)3) does not have secondary or tertiary hydrogens.
Correct answer: Neo- pentane- A. 80%
- B. 5%
- C. 65%
- D. 20%
Explanation: Gasoline produced by fractional distillation is 20% .
Correct answer: 20%- A. Reforming
- B. Distillation
- C. Cracking
- D. Decomposition
Explanation: Reforming is a process in which hydrocarbons are converted into more branched or cyclic hydrocarbons by rearranging the carbon-carbon…
Correct answer: Cracking- A. Cracking
- B. Reforming
- C. Decomposition
- D. Isomerisation
Explanation: Fuels with a higher octane number can be produced by reforming. Reforming is a refining process used in the petroleum industry to increase…
Correct answer: Reforming- A. 100
- B. 95
- C. 9
- D. 89
Explanation: The octane number is a measure of a fuel's ability to resist knocking or detonation during combustion in an internal combustion engine.
Correct answer: 100- A. Reduction reaction
- B. Kolbe's reaction
- C. Clemmensen Reaction
- D. Hydrogenolysis
Explanation: OPTION A: Reduction reactions produce alkanes with unsymmetrical carbon chains, not symmetrical alkanes.OPTION B: Kolbe's Electrolysis…
Correct answer: Kolbe's reaction- A. 0.8
- B. 0.85
- C. 0.7
- D. 0.98
Explanation: Natural gas typically contains about 75-90% methane. So, the correct answer would be 0.85.
Correct answer: 0.85- A. CO2 & H2O
- B. CO & H2O
- C. CO2 & H2
- D. CH3OH
Explanation: Catalytic oxidation of lower alkanes takes place in the presence of a metallic catalyst, for example, Cu, at high temperature and…
Correct answer: CH3OH- A. Reforming
- B. Cracking
- C. Isomers
- D. Decomposition
Explanation: Reforming is a catalytic process in which straight- chain molecules are converted to branched forms. Hence, option A is correct
Correct answer: Reforming