1. Useful Products from Organic Sources
ORGANIC CHEMISTRY

3. How coal formed
Millions of years ago trees died and fell to the bottom of swamps.
Over time they became covered by mud and rock.
…the trees became fossilized, forming coal.
Over millions of years, due to high temperatures and pressure…

4. How oil and natural gas formed

5. Hydrocarbons are molecules that contain carbon and hydrogen only.
Crude oil
Crude oil is a mixture.
It contains hundreds of different compounds. Some are small but most are large.
Nearly all of these compounds contain carbon and hydrogen only.
They are called hydrocarbons.
Also some other compounds contain small amounts of N and S. Why?
Hydrocarbons are molecules that contain carbon and hydrogen only.

6. How oil and natural gas formed
Q1 Explain why oil contains carbon and hydrogen.
Q2 Explain where the energy in oil originated.

7. The importance of oil
The hydrocarbons in crude oil are essential to our way of life
We use them as fuels for most forms of transport.
We also use them as raw materials from which a HUGE range of useful everyday substances are made .. Such as…………..make a list!

8. Making oil useful
Crude oil is a mixture of hydrocarbons with a VERY wide range of sizes.
Crude oil itself has no uses because its properties are
not definite.
To make crude oil into useful substances we have to separate the mixture into molecules of similar size.
This is done in an oil refinery in a process called fractional distillation.
The physical property used to separate the fractions is boiling point.

9. Fractional Distillation

10. Fractional Distillation
Can you predict and explain where the fractions are obtained from the fractionating tower?
cool
hot
Fuel gas
Petroleum
Fraction
Boiling Range
(oC)
Kerosene
Diesel
220 – 275
Petrol
Bitumen
>350
Fuel gas
Below 40
Lubricating oil
Kerosene
Diesel
Lub. Oil
Bitumen

11. Fractional Distillation
Why do these fractions condense over a boiling range?
cool
hot
Fuel gas
Fraction
Boiling Range (oC)
Fuel gas
Below 40
Petrol
Kerosene
Diesel
220 – 275
Lubricating oil
Bitumen
>350
Petroleum
Kerosene
Diesel
Lub. Oil
Bitumen

12. Uses of each fraction Fuel gas Petrol / gasoline Naphtha Paraffin /
Burned in the refinery to fuel the distillation process, sold as LPG, purified and sold as bottled camping gas
Fuel gas
Petrol
/ gasoline
Fuel for cars and motorcycles, also used to make chemicals.
Naphtha
Used to make chemicals used everwhere.
Paraffin /
Kerosine
Fuel for greenhouse heaters and jet engines, manufacture of chemicals.
Diesel fuel
Fuel for lorries, trains.
Fuel and
lubricating
oil
Fuel for the heating systems of large buildings, fuel for ships, lubricating oil.
Bitumen
Roofing, and road surfaces.

13. Why are the fractions useful?

14. Similarities between crude oil and its fractions:
Differences between crude oil and its fractions:

15. The boiling points of molecules
In general, the bigger the molecule the higher the boiling point.
No. Carbon atoms  
B.Pt
(oC)

16. Fraction Boiling Range (oC) Number of carbons 1-5 5-10 9-14 13-17
Here are the boiling ranges of some fractions obtained from distillation of petroleum.
Using the previous graph, estimate the size range of the molecules present in each fraction.
Fraction
Boiling Range
(oC)
Number of carbons
Fuel gas
Below 40
Petrol
Kerosine
Diesel
1-5
5-10
9-14
13-17

17. What is crude oil?
Crude oil is a mixture of different sized hydrocarbons. The exact composition depends upon where the oil comes from but typically it contains a lot of big molecules. (Why is this not good?)
Small molecules
Big molecules
Medium molecules

18. Which is a correct statement about crude oil?
A mixture of carbohydrates.
Formed by the decay of dead sea creatures.
Consist of a mixture of very large molecules.
Is purified in an oil rig.

19. Which is a correct statement about fractional
distillation?
Oil is separated into fractions with the same size molecule.
Oil is separated into fractions with the same density.
Oil is separated into fractions with similar size molecules.
Oil is separated into alkanes and alkenes.

20. Which is a correct order for these fractions working down from the top of the column?
Fuel gas, kerosene, petrol, diesel, bitumen.
Fuel gas, diesel, kerosene, petrol, bitumen.
Fuel gas, petrol, diesel, kerosene, bitumen.
Fuel gas, petrol, kerosene, diesel, bitumen.