5.2.1 Alkanes

Name the first three alkanes in the alkane series.

• Butane

• Octane

• Hexane

• Methane, Ethane, Propane

Explain the concept of structural isomerism in alkanes.

• Structural isomerism in alkanes is only observed in odd-numbered carbon chains.

• Structural isomerism in alkanes occurs due to compounds having same molecular formula but different structural formula

• Structural isomerism in alkanes is caused by the same arrangement of carbon atoms in a molecule, resulting in identical compounds.

• Structural isomerism in alkanes occurs due to compounds having same structural formula but different molecular formula

How do melting and boiling points of alkanes change with increasing molecular weight?

• Melting and boiling points of alkanes increase with increasing molecular weight.

• Melting and boiling points of alkanes are not affected by molecular weight.

• Melting and boiling points of alkanes remain constant with increasing molecular weight.

• Melting and boiling points of alkanes decrease with increasing molecular weight.

What is the color and state of alkanes at room temperature?

• Blue, liquid

• Colorless, gaseous or liquid

• Yellow, solid

• Green, gaseous

What type of reaction do alkanes undergo with halogens in the presence of UV light?

• Decomposition reaction

• Addition reaction

• Substitution reaction

• Oxidation reaction

What are the products of complete combustion of alkanes?

• Methane and oxygen

• Hydrogen and nitrogen

• Carbon dioxide and water

• Carbon monoxide and water

Explain why alkanes are considered to be relatively unreactive compared to other hydrocarbons.

• Alkanes have only single bonds between carbon atoms.

• Alkanes have triple bonds between carbon atoms.

• Alkanes are highly reactive due to their structure.

• Alkanes contain oxygen atoms in their structure.

Which formula represents an unsaturated hydrocarbon?

• A
• B
• C
• D

What is a functional group?

• Atoms or group of atoms that give specific characteristics to a molecule

• Group of molecules that make up a group of atoms

• Group of molecules that give specific characteristics to an atom

• Group of atoms that give specific characteristics to an element

2,2-dimethylpropane has the same number of carbons as

• propane

• butane

• pentane

• hexane