Alcohols

• The general formula for alcohols is CnH2n+1OH.
• Alcohols are organic compounds that contain the hydroxyl functional group (-OH).
• When the hydroxyl group is added to the end of the chain it is written in brackets e.g., CH3CH(OH)CH2CH3
• Alcohols are formed when halogenoalkanes undergo nucleophillic substitution with aqueous hydroxides
• When classifying haloalkanes, we classify them according to the number of carbons bonded to the c-x carbon.
• Primary alcohols have one alkyl group attached to the carbon atom bearing the OH group (e.g., ethanol)
• Secondary alcohols have two alkyl groups attached to the carbon atom bearing the OH group (e.g., propan-2-ol)
• Tertiary alcohols have three alkyl groups attached to the carbon atom bearing the OH group (e.g., butan-2-ol)
• When we have an alkane, where two hydrogen's are replaced by a hydroxyl group we call this a....

  Diol
• What is a diol?

  A compound containing two -OH functional groups on adjacent carbon atoms.
• How to name a diol

  • write full name of longest carbon chain
  • Add diol
  • Add position numbers to each hydroxyl group
• Always use the lowest position number first when naming diols
• strongest intermolecular force in alcohols is?

  hydrogen bonding
• alkenes only have van der waals forces
• alkenes are gases at room temp
• What is volatility?

  how easily something evaporates
• Alcohols are less volatile than alkenes
• As chain length increases

  • strength of van der waals increases
  • boiling point and melting point increases
• Because oxygen is more negative than hydrogen we say that the oxygen-hydrogen bond is polar.
• small alcohols are highly soluble
• As length of carbon chain increases solubility decreases due to non-polar substances being highly insoluble in polar substances