All Free Chemistry MCQs with Answers

• 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…

• 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.

• 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…

• 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.

• 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…

• 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.

• 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…

• 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.

• A. Steam cracking
• B. Reforming
• C. Catalytic cracking
• D. Distillation

Explanation: The octane number of gasoline is improved by a process called 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…

• 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.

• 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…

• 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.

• 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].

• A. 40
• B. 100
• C. Zero
• D. 2

Explanation: Octane number means the ability of any fuel to resist knocking when it is ignited in a mixture of air.

• A. 96 litres
• B. 9.6 litres
• C. 44.8 litres
• D. 67.2 litres

Explanation: 4gm of Ethylene (C2H4) = 0.1428 moles or 3.2L of it. The Balanced Chemical Equation for this reaction is: C2H4+ 3O2 -> 2CO2 + 2H2O+ energy…

• A. Alkanes
• B. Alkenes
• C. Alkynes
• D. Benzene

Explanation: Alkanes are least reactive, followed by benzene. Alkenes are more reactive than alkynes.

• A. sp2
• B. sp3
• C. sp2d
• D. sp

Explanation: Remember that alkanes have sp3 hybridization, alkenes have sp2 hybridization and alkynes have sp hybridization.

• A. Ethane
• B. Ethyne
• C. Ethylbenzene
• D. Ethene

Explanation: Alkanes cannot be oxidized; rather they can be oxidized only when burned in the presence of O2 to give carbon dioxide and water.

• A. Alkanes
• B. Alkenes
• C. Alkynes
• D. All of the above options are correct

Explanation: Geometric Isomerism results most commonly from C=C. The important property which introduces the feature is the inability of the Carbon…