unit 2.3 wider impact of chemistry

• what causes the greenhouse effect

  absorption of the infrared radiation by specific bonds within substances
• what bonds cause radiation to stay in the atmosphere

  • $C=$$O$
  • $O-H$
  • $C-H$
• crude oil

  raw natural resource extracted from the earth and refined into gasoline, jet fuel and outer petroleum products
• fracking

  extraction technique for oil and gas wells in which rocks are fractured atrificially using pressurized liquid
• shale gas

  extracted from impermeable rock through fracking, can generate electricity for domestic heating and cooking
• biofuels

  liquid fuels produced from renewable biological sources, plants and algae
• biodiesel

  fuel manufactured by vegetable oils, animal fats or recycled restaurant grease
• bioethanol

  ethanol produced from plants (sugar cane or maize) used as an alternative fuel
• hydrogen

  clean fuel, when consumed in fuel cell produces onyl water, used as rocket fuel
• CFC's

  damage the earths ozone layer, can be harmful to humans can be used as solvents and in aerosols. used in cars airconditioning and for cleaning electronic sensors
• advantages of catalysts

  lower energy requiremets needed for a reaction, allows for use of less toxic materials, decreased use of processing and separation agents. potential for incorperating renewable energy
• disadvantages of catalysts

  many catalysts are toxic and can escape into the environment, expensive, can be effected by impurities
• advantages of biodiesel

  improves public health, safety benefits, contributes to transportation system
• disadvantages of biodiesel

  lower energy output than normal diesel, energy clogging, insuitable in cold reigons, still pollute air