Chemistry Revision

1
Chemistry Revision

• Session 6

2
Recap of isomerism

• Define the term Isomers, and draw an example,
  naming each isomer.

3
Octane Numbers

• Explain why a fuel needs to have high octane
  rating.
• Give 3 ways I can increase the octane rating of a
  fuel

4
Catalysts

• Define the term catalyst
• The reaction of nitrogen and hydrogen gases using
  a solid iron catalyst is an example of which type
  of catalysis?
• On the following diagram draw on an energy
  profile for uncatalysed and catalysed (with
  intermediate) reactions. Add the Activation
  Enthalpies and label the intermediate and ?H

5
Is it endothermic? Yes or No
6
Catalysts again

• Explain the terms adsorbed and catalyst poison.
• An industrial process requires a gold catalyst-
  give 2 advantages to it be a thin film of gold
  powder on a iron coil

7
Answers

• Adsorbed makes bonds to the surface of a
  substance
• Catalyst poison is more strongly adsorbed onto
  the surface of the catalyst- reducing its
  efficiency
• Cheaper and increased SA

8
Pollutants

• My old car used petrol and my new car uses pure
  ethanol.
• Explain how the following pollutants are formed
  in a car engine and explain which of the two
  engines they would be made in
• Carbon dioxide, nitrogen dioxide, sulphur dioxide
  and carbon monoxide

9
Cracking

• Explain the purpose of cracking an alkane.
• Explain the term entropy.
• When cracking what will happen to entropy- why?

10
Alkenes

• Give the general molecular formula for an alkene
• Describe the test for an alkene- what will I see
• Draw out the full structural formula of propene.
  Identify the bond angle at C1 and at C3

11
Desirable fuels

• Ignoring pollution- gives 3 properties a good
  fuel should have