1. Substances from Crude Oil

2. What do I need to know?
Recall how hydrocarbons can be cracked to make smaller more useful molecules.
Describe some of the properties of alkenes
Explain how alkenes can be used to synthesise polymers for a wide range of different applications.

3. Supply and demand
Oil companies have to balance supply and demand for the different fractions of crude oil.
For example petrol may be higher in demand than diesel but the oil company may have less of it.
How can they overcome these problems?

4. Supply and demand – the options
Oil companies can make the fraction that is in demand more EXPENSIVE
Oil companies can lobby the Government to make changes to the system of TAXATION.
Oil companies can make more of the fraction that is in demand, for example by CRACKING.

6. Catalytic Cracking
The larger fractions from crude oil can be of limited value as fuels or as chemical feedstock.
To make these more useful and therefore more valuable they are split into smaller molecules using a process called CRACKING.

7. Heat the hydrocarbons to vaporise Pass over a hot catalyst OR
Heat to high temperature with steam
Decomposition then occurs
Shorter alkenes and alkanes formed

10. Recap - Alkenes
Alkenes are hydrocarbons with double bonds between carbon atoms.
One double bond is enough, it does not need to be between every carbon atom.
Examples are ETHENE and PROPENE

11. The general formula
CnH2n

13. Test for Alkenes
Bromine water is an orangey solution. It is orange because it contains bromine molecules (Br2)
When you add bromine water to an alkene it turns colourless.

14. Test for alkenes

15. Substances from Crude Oil
Polymerisation
Substances from Crude Oil

16. What do I need to know?
Recall the many different uses and applications of polymers
Describe how a polymer is made from monomers and how to draw monomers and polymers
Explain the problems that are caused by polymers that are not biodegradeable.

17. Polymerisation
In polymerisation many small molecules MONOMERS join together to form a larger molecule POLYMER sometimes containing many thousands of monomers.

18. Polymerisation

19. Drawing monomers and polymers

20. Uses of polymers Cling film/cellophane Non stick coating (Teflon)
Tights and clothing (Nylon, Lycra)
Windows and doors (uPVC)
Bottles and food packaging
Waterproof coatings for fabrics (Goretex)
Dental polymers
Wound dressings especially for burns
Hydrogels for use in nappies.
Smart materials such as memory foam.

21. Waste disposal Many polymers are not biodegradeable
This means they are not broken down by microbes
This can lead to problems with waste disposal

22. Remedies
Plastic bags are being made from polymers and cornstarch so that they break down more easily.
Biodegradeable plastic plastics are now widely used