Alkenes

• What type of bond do alkenes have?

  Alkenes have a carbon-carbon double bond.
• Why are alkenes considered unsaturated?

  Because they have fewer hydrogen atoms compared to alkanes due to the presence of a double bond.
• How does the presence of a double bond in alkenes affect their reactivity?

  The double bond makes alkenes more reactive than alkanes.
• What are the general formulas for alkenes?

  • General formula: C_nH_2n
  • Example: Ethene (C₂H₄), Propene (C₃H₆), Butene (C₄H₈), etc.
• What is the combustion product of alkenes when there is a sufficient amount of oxygen?

  Water and carbon dioxide are produced.
• What happens during incomplete combustion of alkenes?

  Incomplete combustion produces carbon monoxide and soot in addition to carbon dioxide and water.
• What is the result of incomplete combustion of alkenes in terms of flame appearance?

  It results in a smoky yellow flame.
• What is the chemical equation for the incomplete combustion of carbon?

  C + O₂ → CO + CO₂ + H₂O + energy
• How do you determine the number of carbon atoms in an alkene based on its name?

  The first part of the name indicates the number of carbon atoms.
• What is the chemical formula for the alkene that contains eight carbon atoms?

  C₈H₁₆
• What is the significance of the letter 'e' in the names of alkenes?

  The letter 'e' indicates that the compound is an alkene, distinguishing it from alkanes.
• What are the key characteristics of alkenes?


  • Contain a carbon-carbon double bond
  • Unsaturated hydrocarbons
  • More reactive than alkanes
  • General formula: C_nH_2n