alcohols

• what are two uses of methanol?

  1. feedstock
  2. petrol additive to improve combustion
• what are two uses of ethanol?

  1.alcohol drinks

  2.solvent in the form of methylated spirits
• general formula: $CnH2n+$$2OH$
• ethanol can form hydrogen bonds with water
• solubility: alcohols have polar O-H bonds, so form hydrogen bonds with water
• volatility: ability of a substance to turn into a gas
• the lower the boiling point the more volatile the cmpound
• alcohols have hydrogen bonds, hydrogen bonds are stronger, more OH groups, stronger hydrogen bonding
• • boiling point increases as the chain length increases
  • London dispersion forces increases
  • more energy needed to overcome
• • boiling point decrease as branching increases
  • because of less surface area of contact
  • less London dispersion forces
• what are two processes to manufacture ethanol?

  fermentation and hydration
• fermentation equation:

  C6H12O6 (aq) --> 2C2H5OH (l) + 2CO2 (g)
• hydration:

  CH2=CH2 (g) + H2O (g) --> Ch3Ch2OH (l)
• sustainability of fermentation:

  glucose is renewable - obtained from plants
• sustainability of hydration:

  no waste - atom economy is 100%

  BUT ethene is obtained from cracking fractions of crude oil