1. Organic Chemistry Revision
Grade 10

2. It is a mixture of hydrocarbons.
What is crude oil?
It is a mixture of hydrocarbons.

3. How was crude oil formed?
From the buried remains of
animals and plants
over millions of years
High pressure and
temperature.

4. Are compounds made up of hydrogen and carbon only.
What are hydrocarbons?
Are compounds made up of hydrogen and carbon only.

5. What is the name of the process used for separating crude oil?
Fractional distillation

6. What is the name of the apparatus used for separating crude oil?
Fractionating column

7. Name four fractions produced by fractional distillation.
Refinery gas
Petrol
Gasoline
Kerosene
Diesel bitumen

8. Short fractions at the top Long fractions at the bottom
Referring to the size of the hydrocarbon, which one fraction will be collected at the top? At the bottom of the fractionating tower?
Short fractions at the top
Long fractions at the bottom

9. What are the products of the complete combustion of a hydrocarbon?
Carbon dioxide and water vapour

10. What are the products of the incomplete combustion of a hydrocarbon?
Carbon monoxide and water vapour

11. What is the name of the poisonous gas produced by incomplete combustion?
Carbon monoxide

12. What is the effect of this gas on health?
Carbon monoxide is a poisonous gas.
It decreases the oxygen carriers in blood.
It may cause death if its level in blood is high.

13. How can you break long chain hydrocarbons?
By cracking

14. What is the difference between cracking and fractional distillation?
Cracking is a chemical process while fractional distillation is a physical process.

15. What are the conditions for cracking?
High temperature
catalyst

16. What is a homologous series?
Members of the series have the Same general formula.
Similar chemical properties Successive members differ by CH2 similar physical properties such as appearance, melting/boiling points,

17. What is the general formula of alkanes?
Cn H2n+2

18. What is the general formula of alkenes?
Cn H2n

19. Give the molecular formula of: ethane propene butene methane
C2 H6
C3 H6
C4 H8
C H4

20. Draw the structural formula of propane

21. Draw the structural formula of butene

22. What is the chemical test used to differentiate between alkanes and alkenes? what is the result?
Bromine water test
The bromine will decolorize in alkenes and stays orange brown in alkanes.

23. Write the polymerization reaction of polyethene.

24. Name two other polymers and draw their monomers then name them.
Polypropene
polychloroethene C H
CH3 C H Cl