Q1-3:   Crude oil is separated into different fractions by fractional distillation.

Crude oil distiller
Terry Joyce | CC by S.A. 2.0

1. Before entering the column the crude oil must be ..
  • A.   cooled to condense it
  • B.   cooled to evaporate it
  • C.   heated to condense it
  • D.   heated to evaporate it
2. The physical property which allows the different fractions in crude oil to be collected at different heights in the column is ..
  • A.   boiling point
  • B.   density
  • C.   melting point
  • D.   viscosity
3. The fraction which collects at the top of the column has …
  • A.   small molecules with a low boiling point
  • B.   small molecules with a high boiling point
  • C.   large molecules with a low boiling point
  • D.   large molecules with a high boiling point

Q4- 6. Four fractions obtained from fractional distillation of crude oil are fuel oil, petrol, kerosene and diesel. The fraction which …..

4. ...has the highest boiling point is .
5. ...contains molecules with the least number of carbon atoms is .
6. ...is used as fuel for aeroplanes is .

7. As the number of carbon atoms in a hydrocarbon molecule increases the ease of ignition, boiling point and viscosity change in the following way:

  Ease of ignition Boiling point viscosity
A decreases decreases decreases
B decreases increases increases
C increases increases decreases
D increases increases increases

Q8-12 Combustion of hydrocarbon fuels can produce carbon dioxide, carbon monoxide, sulfur dioxide and oxides of nitrogen.


8. The correct word equation for the complete combustion of a hydrocarbon fuel is ..

  • A.  fuel  +  oxygen  carbon dioxide + water
  • B.  fuel  +  oxygen  carbon dioxide +  hydrogen
  • C.  fuel  +  oxygen  carbon monoxide + water
  • D.  fuel  +  oxygen  carbon monoxide + hydrogen
9. Carbon monoxide is dangerous because it …
  • A.  causes global warming
  • B.  causes acid rain
  • C.  limits the blood from carrying oxygen
  • D.  limits the blood from carrying carbon dioxide

10. Carbon dioxide and sulfur dioxide cause the following pollution problems….

  Carbon dioxide Sulfur dioxide
A Global warming Global warming
B Global warming Acid rain
C Acid rain Global warming
D Acid rain Acid rain
11. Oxides of nitrogen are formed by …
  • A.   nitrogen impurities in the fuel burning
  • B.   oxides of nitrogen being released from within the fuel
  • C.   high temperatures causing oxygen and nitrogen from the air to combine
  • D.   high temperatures causing nitrogen impurities to oxidise
12. Hydrocarbons are molecules containing…
  • A. carbon and hydrogen atoms
  • B. carbon and hydrogen atoms only
  • C. only single C-C and C-H bonds
  • D. at least one double C=C bond