Alkanes: Saturated Hydrocarbons

Alkanes

Definition

• Alkanes are a type of saturated hydrocarbon, meaning they have only single bonds between carbon atoms.
• They are also known as paraffins or saturated hydrocarbons.

General Formula

• The general formula for alkanes is CnH2n+2, where n is the number of carbon atoms.

Nomenclature

• Alkanes are named using the IUPAC system, which follows these rules:
  • The parent chain is the longest continuous chain of carbon atoms.
  • The parent chain is numbered starting from the end that is closest to a branch.
  • Branches are named as substituents and are numbered based on their position on the parent chain.
  • The suffix "-ane" is used to indicate that the molecule is an alkane.

Physical Properties

• Alkanes are non-polar and have low boiling points, which increase as the number of carbon atoms increases.
• They are insoluble in water and have a density less than that of water.

Chemical Properties

• Alkanes are relatively unreactive, except for combustion reactions.
• They undergo substitution reactions, where a hydrogen atom is replaced by another atom or group.
• They also undergo cracking reactions, where a large alkane is broken down into smaller ones.

Examples

• Methane (CH4) is the simplest alkane.
• Ethane (C2H6) is another example of an alkane.
• Octane (C8H18) is a common alkane found in gasoline.

Isomerism

• Alkanes can exhibit structural isomerism, where the same molecular formula has different bond arrangements.
• For example, butane (C4H10) has two structural isomers: n-butane and isobutane.

Alkanes

• Alkanes are saturated hydrocarbons with only single bonds between carbon atoms, also known as paraffins or saturated hydrocarbons.

General Formula and Structure

• The general formula for alkanes is CnH2n+2, where n is the number of carbon atoms.

Nomenclature

• Alkanes are named using the IUPAC system, with rules including:
  • Identifying the longest continuous chain of carbon atoms as the parent chain
  • Numbering the parent chain starting from the end closest to a branch
  • Naming branches as substituents and numbering based on their position
  • Using the suffix "-ane" to indicate an alkane

Physical Properties

• Alkanes are non-polar and have low boiling points that increase with the number of carbon atoms
• They are insoluble in water and have a density less than that of water

Chemical Properties

• Alkanes are relatively unreactive, except for combustion reactions
• They undergo substitution reactions, where a hydrogen atom is replaced by another atom or group
• They also undergo cracking reactions, where a large alkane is broken down into smaller ones

Examples

• Methane (CH4) is the simplest alkane
• Ethane (C2H6) is another example of an alkane
• Octane (C8H18) is a common alkane found in gasoline

Isomerism

• Alkanes can exhibit structural isomerism, where the same molecular formula has different bond arrangements
• For example, butane (C4H10) has two structural isomers: n-butane and isobutane