alkanes

• What are alkanes classified as?

  A homologous series of saturated hydrocarbons
• What defines a homologous series?

  Compounds with the same functional group
• What is the general formula for an alkane?

  $C_nH_{2n+2}$
• What does the general formula $C_nH_{2n+2}$ indicate about hydrogen atoms?


  Twice as many hydrogen atoms plus two
• What are the first four alkanes?

  Methane, ethane, propane, butane
• Why are alkanes considered saturated?

  All atoms have formed maximum bonds
• How many bonds does carbon form?

  Four bonds
• How many bonds does hydrogen form?

  One bond
• What happens to the energy required to break alkane molecules as they get bigger?

  It increases
• How do the boiling points of alkanes change with size?

  Boiling points increase with larger alkanes
• What trend is observed in the viscosity of larger alkanes?

  They become more viscous
• Which alkane has the highest boiling point among the first four?

  Butane
• Which alkane is the most flammable?

  Methane
• Why is methane considered useful as a fuel?

  It is highly flammable
• If an alkane has six carbon atoms, how many hydrogen atoms does it have?

  14 hydrogen atoms
• What is the formula for an alkane with six carbon atoms?

  $C_6H_{14}$
• How many hydrogen atoms does an alkane with 10 carbon atoms have?

  22 hydrogen atoms
• What is the formula for an alkane with 10 carbon atoms?

  $C_{10}H_{22}$
• If an alkane has 38 hydrogen atoms, how many carbon atoms does it have?

  18 carbon atoms
• What is the formula for an alkane with 38 hydrogen atoms?

  $C_{18}H_{38}$
• What are the steps to determine the molecular formula of an alkane from carbon atoms?

  1. Identify the number of carbon atoms (n).
  2. Calculate $2n$ for hydrogen atoms.
  3. Use $2n +$$2$ for the final count.
  4. Write the formula as $C_nH_{2n+2}$.
• Why does propane have a lower boiling point than butane?

  Because propane is smaller
• What is the molecular formula for an alkane with seven carbon atoms?

  $C_7H_{16}$
• What is the molecular formula for an alkane with 24 carbon atoms?

  $C_{24}H_{50}$
• What is the molecular formula for an alkene with 26 hydrogen atoms?

  $C_{12}H_{26}$
• What are the properties of alkanes?

  • Saturated hydrocarbons
  • Increase in boiling point with size
  • More viscous with size
  • Less flammable with size