Alkene Properties Quiz

Alkene Definition

• An alkene is a type of unsaturated hydrocarbon that contains one or more carbon-carbon double bonds.
• General formula: CnH2n
• Also known as olefins

Physical Properties

• Alkenes are generally colorless, volatile, and flammable liquids or gases
• They have a characteristic sweet or pungent odor
• Boiling points and melting points increase with increasing molecular weight
• Solubility: generally insoluble in water, but soluble in organic solvents

Chemical Properties

• Alkenes are reactive due to the presence of the double bond
• They can undergo addition reactions, such as:
  • Electrophilic addition (e.g. hydrogenation, halogenation)
  • Nucleophilic addition (e.g. hydrolysis, oxidation)
• They can also undergo polymerization reactions to form polymers

Nomenclature

• Alkene names end in "-ene"
• Numbering of the parent chain starts from the end that is closest to the double bond
• Substituents are named and numbered accordingly
• Example: 1-butene (CH₃CH₂CH=CH₂)

Isomerism

• Alkenes can exhibit structural isomerism (different bond connections) and stereoisomerism (same bond connections, but different 3D arrangements)
• Cis-trans isomerism is a type of stereoisomerism that occurs in alkenes with different substituents on the double bond

Preparation

• Alkenes can be prepared through:
  • Dehydrohalogenation of alkyl halides
  • Dehydration of alcohols
  • Cracking of petroleum fractions
  • Catalytic cracking of alkanes

Alkene Definition and Properties

• Alkenes are unsaturated hydrocarbons with one or more carbon-carbon double bonds.
• General formula: CnH2n.
• Also known as olefins.

Physical Properties

• Colorless, volatile, and flammable liquids or gases.
• Characteristic sweet or pungent odor.
• Boiling points and melting points increase with increasing molecular weight.
• Generally insoluble in water, but soluble in organic solvents.

Chemical Reactions

• Reactive due to the presence of the double bond.
• Undergo addition reactions, including:
  • Electrophilic addition (e.g., hydrogenation, halogenation).
  • Nucleophilic addition (e.g., hydrolysis, oxidation).
• Can undergo polymerization reactions to form polymers.

Nomenclature

• Alkene names end in "-ene".
• Numbering of the parent chain starts from the end closest to the double bond.
• Substituents are named and numbered accordingly.
• Example: 1-butene (CH₃CH₂CH=CH₂).

Isomerism

• Exhibit structural isomerism (different bond connections) and stereoisomerism (same bond connections, but different 3D arrangements).
• Cis-trans isomerism is a type of stereoisomerism that occurs in alkenes with different substituents on the double bond.

Preparation

• Can be prepared through:
  • Dehydrohalogenation of alkyl halides.
  • Dehydration of alcohols.
  • Cracking of petroleum fractions.
  • Catalytic cracking of alkanes.