hydrocarbons exam qs

• What is an unsaturated hydrocarbon?

  A compound that contains hydrogen and carbon only and there are double bonds between carbon atoms.
• Propene can be made by using heat to compose large alkane molecules into smaller, more useful molecules. What is this process?

  Cracking
• What is seen when a sample of propene is shaken with bromine water?

  Bromine water turns from orange to colourless
• What is this structure?

  Poly(propene)

  
• State a property of poly(propene) that makes it suitable for use as ropes on boats:

  Waterproof, flexible
• What is a problem caused by the disposal of poly(propene) ropes in landfill sites?

  Does not decompose, is not biodegradable
• What is this structure?

  Propene

  
• What is a saturated hydrocarbon?

  Contains carbon and hydrogen atoms only and there are only single bonds
• Octane is mixed with bromine water and is shaken, what colour does the mixture turn?

  It remains orange
• Why is it necessary to carry out cracking to make more petrol from fuel oil?

  There is higher demand for petrol and petrol is more useful than fuel oil
• What is the formula for methane?

  CH4
• What occurs in the hydrogenation of a liquid oil?

  The liquid oil is changed into a solid
• What is a suitable alkali to use in the production of soaps?

  Sodium hydroxide
• How do soap anions remove grease marks from clothes during washing with water?

  Surface tension is lowered. Grease is surrounded by soap as the tail end is in grease and the head (anion) end is in water
• What are the uses of polyesters?

  Plastic bottles, bedding, ropes, clothing
• What is CH3CH3?

  A hydrocarbon
• What is the formula of this?

  C3H6

  
• What are the advantages of using bio-methane rather than natural gas as a source of energy?

  Renewable, more plants can be grown, crops use up carbon dioxide and produce oxygen, does not use up crude oil or non-renewable resources
• What are the disadvantages of using bio-methane rather than natural gas as a source of energy?

  Crops grown for bio-methane use up land when it could be used for homes, there are lots of crops required to provide bio-methane, there are carbon emissions due to transport