Alkane Quiz

What is the general chemical formula for alkanes?

• CnH2n-2

• CnH2n+2

• CnH2n

• CnH2n-4

Answer explanation

The general chemical formula for alkanes is CnH2n+2, where n represents the number of carbon atoms in the alkane chain.

Which type of hydrocarbons are referred to as cycloalkanes?

• Unsaturated hydrocarbons

• Branched alkanes

• Linear alkanes

• Saturated cyclic hydrocarbons

Answer explanation

Saturated cyclic hydrocarbons are referred to as cycloalkanes because they consist of closed-ring structures with only single bonds between carbon atoms.

What is the angle between the bonds in an alkane molecule?

• 90 degrees

• 109.47 degrees

• 120 degrees

• 180 degrees

Answer explanation

The angle between the bonds in an alkane molecule is 109.47 degrees, which is the correct answer choice provided.

Which type of alkanes have lower values of standard enthalpy change of combustion?

• Cyclic alkanes

• Branched-chain alkanes

• Unsaturated alkanes

• Straight-chain alkanes

Answer explanation

Branched-chain alkanes have lower values of standard enthalpy change of combustion due to their increased stability compared to straight-chain alkanes.

What is the primary product of the combustion of alkanes in the presence of sufficient oxygen?

• Soot

• Carbon dioxide

• Carbon monoxide

• Water

Answer explanation

The primary product of the combustion of alkanes in the presence of sufficient oxygen is carbon dioxide.

What is the process that breaks larger molecules into smaller ones with the help of heat and catalysts?

• Polymerization

• Hydrogenation

• Cracking

• Isomerization

Answer explanation

Cracking is the process that breaks larger molecules into smaller ones with the help of heat and catalysts.

Which type of cracking process involves the presence of acid catalysts promoting a heterolytic breakage of bonds?

• Reformation

• Catalytic cracking

• Thermal cracking

• Isomerization

Answer explanation

Catalytic cracking involves the presence of acid catalysts promoting a heterolytic breakage of bonds.

What is the most common alkane put under the process of isomerization to produce branched alkanes with high octane numbers?

• Butane

• Propane

• Methane

• Ethane

Answer explanation

The most common alkane put under the process of isomerization to produce branched alkanes with high octane numbers is Butane.

In which reaction do alkanes react with steam in the presence of a nickel catalyst to give hydrogen and carbon monoxide?

• Isomerization

• Steam reforming

• Reformation

• Cracking

Answer explanation

In the reaction of alkanes with steam in the presence of a nickel catalyst, the process is known as steam reforming, which produces hydrogen and carbon monoxide.

What is the most important commercial source for alkanes?

• Natural gas

• Petroleum jelly

• Biomass

• Coal

Answer explanation

The most important commercial source for alkanes is natural gas, which is a fossil fuel primarily composed of methane and other hydrocarbons. It is widely used for heating, electricity generation, and as a feedstock for various chemical processes.