Tuesday, May 17, 2011

5.13 I can describe catalytic cracking of long-chain hydrocarbons

Define the term catalyst
Catalyst - A substance that changes the rate of chemical reaction.

Why is a catalyst used?
Catalyst is used to speed up reaction so more products could be made in a shorter range of time.

Why are high temperatures needed?
The high temperatures are needed to provide the energy to break the strong covalent bonds in the molecule.
High temperatures also vary the rate of reaction because the particles move faster, they will have more chance of collision therefore increase the rate of reaction.







What is the process called to convert long chain hydrocarbons to short chain hydrocarbons
Cracking

How are the bigger molecules broken down
By Heating

Crackling is an example of what decomposition reaction
Thermal decomposition reaction

Why are catalyst needed in cracking
To speed up reaction

Why do we need to crack hydrocarbons
To produce more useful stuff such as Refinery Gas or Petrol

What gas is produced from cracking Paraffin
Ethene

 What is the catalyst for cracking paraffin
Aluminium Oxide





1 comment:

  1. 5.13 Q3 The high temperatures are needed to provide the energy to break the strong covalent bonds in the molecule, the fact that the rate increases in a bonus! Great questions Eri. Please change the background of your posts to white (go to the design section to do this) so that the answers are not visible.

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