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 5 of 7
- A. 0
- B. 100
- C. 40
- D. 98
Explanation: If there is pure n-heptane, then its octane number is 0. n-heptane has zero octane number because of very poor knock resistance.
Correct answer: 0- A. Decrease the boiling point
- B. Prevent heating
- C. Prevent freezing of fuel
- D. Prevent knocking
Explanation: Organic lead (tetraethyl lead; TEL) is used as an antiknock agent in gasoline and jet fuels. It increases the octane number of the fuel.
Correct answer: Prevent knocking- A. Tetramethyl lead
- B. Tetraethyl lead
- C. Iso-octane
- D. All of these
Explanation: Option A is incorrect as tetramethyl lead doesn't have anti-knocking properties.
Correct answer: Tetraethyl lead- A. C- C
- B. C-H
- C. Both C-C and C-H
- D. C-0
Explanation: Cracking is the process whereby complex organic molecules such as long-chain hydrocarbons are broken down into simpler molecules such as…
Correct answer: C- C- A. C-C
- B. C-H
- C. Both C-C and C-H
- D. C-O
Explanation: The primary types of bonds that are broken during cracking are C-C bonds.
Correct answer: C-C- A. Cracking
- B. Hydrolysis
- C. Oxidation
- D. Distillation
Explanation: Cracking is the process in which long chain hydrocarbons (in liquid/solid state) are broken into short chain, more useful hydrocarbons…
Correct answer: Cracking- A. C-C
- B. C-H
- C. Both C-C and C-H
- D. C-O
Explanation: Option A is correct as cracking is the breakdown of very large chains of carbon into smaller chains by breaking the "Carbon to Carbon…
Correct answer: C-C- A. Methane
- B. Ethane
- C. Propane
- D. Butane
Explanation: a) Methane: Methane is indeed called "marsh gas." It is the simplest hydrocarbon with the chemical formula CH4.
Correct answer: Methane- A. Silica, lime
- B. Silica, alumina
- C. Silica, Soda ash
- D. Alumina,Pt
Explanation: Option B is correct since silica and alumina are used in catalytic cracking to produce smaller more useful fractions from larger…
Correct answer: Silica, alumina- A. Olefines.
- B. Paraffins.
- C. Reactive.
- D. All of these.
Explanation: Paraffin is a term that was originally used to describe a waxy substance that was obtained from petroleum.
Correct answer: Paraffins.- A. Higher the octane number, higher will be the knocking.
- B. Higher the octane number, the efficiency of fuel will be lower.
- C. Higher the octane number, lower the knocking.
- D. Lower the octane number, lower the knocking.
Explanation: Higher octane numbers in gasoline indicate that the fuel is more resistant to knocking, which is a type of uncontrolled combustion that…
Correct answer: Higher the octane number, lower the knocking.- A. 0
- B. 100
- C. 40
- D. 98
Explanation: Option A: n-Heptane (C7H16) has an octane number of 0. Option B: iso-octane (C8H18) has an octane number of 100.
Correct answer: 0- A. Alkene
- B. Alkyne
- C. Alkane
- D. Cycloalkene
Explanation: The correct answer is: Alkane An alkane is a hydrocarbon compound in which all carbon atoms are fully saturated with single covalent…
Correct answer: Alkane- A. Alkanes
- B. Alkenes
- C. Alkynes
- D. All of these options are correct
Explanation: In the alkane series, all the carbon atoms are bonded through C-C single bonds.
Correct answer: Alkanes- A. Steam cracking
- B. Reforming
- C. Catalytic cracking
- D. Distillation
Explanation: The octane number of gasoline is improved by a process called reforming.
Correct answer: Reforming- A. The higher the octane number, the higher will be knocking
- B. Higher the octane number, the efficiency of the fuel will be lower
- C. The higher the octane number, lower will be the knocking
- D. Lower the octane number, lower the knocking
Explanation: The octane number of a fuel represents the quality of fuel, the higher the octane number, the higher the fuel quality and the lesser the…
Correct answer: The higher the octane number, lower will be the knocking- A. Olefines
- B. Paraffins
- C. Reactive
- D. All of these options are correct
Explanation: Alkanes are also called paraffins, while alkenes are also called olefins.
Correct answer: Paraffins- A. Cracking
- B. Hydrolysis
- C. Oxidation
- D. Distillation
Explanation: Correct option is A. Cracking is defined as a process, where in complex organic molecules namely long chain hydrocarbons or kerogens are…
Correct answer: Cracking- A. Reforming
- B. Distillation
- C. Cracking
- D. Decomposition
Explanation: "Cracking" is a process in which long-chain hydrocarbons are broken into small chain hydrocarbons by means of heat and pressure.
Correct answer: Cracking- A. Silica, Lime
- B. Silica, Alumina
- C. Silica, Soda ash
- D. Alumina, pt
Explanation: In the process of catalytic cracking, solid catalysts convert plastics into liquid fuel [lighter fractions].
Correct answer: Silica, Alumina