Isomerization Flashcards
What does isomerization involve?
It involves changing straight-chain alkanes into their isomers
What is the first step in isomerization?
The alkanes are heated in the presence of a suitable catalyst and this causes the chains to break
What is the first step in isomerization?
The alkanes are heated in the presence of a suitable catalyst and this causes the chains to break
What is the effect of heating an alkane in the presence of a catalyst
This causes the chains to break
What do the chains do once they have been broken into fragments?
They join together again which is more likely to form a branched-chain alkane than a straight-chain alkane.
What is likely to form when the chain fragments join together again?
A branched-chain alkane
What is not likely to form when the chain fragments join together again?
A straight-chain alkane
Where is isomerisation carried out on a large scale?
It is carried out in oil refineries on a large scale
Isomerisation is carried out in oil refineries on a large scale on what hydrocarbons?
Pentane
Hexane
Pentane and hexane are found in what fraction obtained from the distillation of crude oil?
They are found in the petrol fraction
What is the octane number of pentane?
62
What is the octane number of hexane?
25
Does the isomerisation go to completion?
No
What should be noted about isomerisation reactions?
They do not go to completion and instead reach a state of equilibrium
What is formed from the isomerisation of hexane and octane from the petrol fraction of crude oil?
A mixture consisting of straight chained and branched isomers is formed
