Fuels 2

• What does exothermic mean?

  Heat energy is being released
• How is crude oil formed?

  Layers of dead sea creatures formed on the sea bed

  Layers of sedimentary rock formed on top and the sea creatures become trapped

  After millions of years oil began to form in the absence of oxygen
• How is coal formed?

  Before the dinosaurs, many giant plants died in swamps

  Over millions of years, the plants were buried under water and dirt

  Heat and pressure turned the dead plants into coal
• How is peat formed?

  The accumulation of decayed organic matter like trees, animal carcasses, moss, grass
• How is natural gas formed?

  Forms alongside other fossil fuels
• How can crude oil be separated into different fractions?

  fractional distillation, by heating it up until it vaporises, then cooling the vapours so that components with different boiling points condense at different levels in the distillation column.
• Describe a combustion reaction

  Hydrocarbons burning to produce carbon dioxide and water
• What is the word equation for a combustion reaction

  hydrocarbon + oxygen --> carbon dioxide + water
• What is ethanol an example of?

  Ethanol is an example of a biofuel
• How is ethanol produced?

  fermentation
• What happens when bio ethanol is burned as a fuel?

  Carbon dioxide is produced
• Why are biofuels considered "carbon neutral"?

  The CO2 they emit is balanced by the CO2 taken up by plants when they are produced (other factors such as shipping and industry can affect this)
• What is fermentation?

  The means of converting sugar source into alcohol
• What catalyst is used in fermentation?

  Yeast
• What is the word equation for fermentation?

  Glucose (sugar) + (yeast) => ethanol/alcohol + carbon dioxide