SS3: Chemistry Theory Questions – Petroleum II

Question 1

Define the following terms:

i. Hydrocarbon

Answer: Hydrocarbon is an organic compound composed exclusively of carbon and hydrogen atoms. They are naturally occurring and form the basis of crude oil, natural gas coal etc.

ii. Cracking of petroleum

Answer: Cracking is the breaking up of longer hydrocarbon into smaller ones at high temperatures and pressure in the presence of catalysts.

iii. Reforming

Answer: Reforming is the conversion of straight-chain hydrocarbons using a catalyst into branch chain isomers, cycloalkanes and benzene. It is used to improve the quality of petrol.

Question 2

Give two differences between cracking and reforming

Answer:

Question 3

How are the fractions of petroleum separated?

Answer:

They are separated using fractional distillation. The fractions are separated according to their molar masses and boiling point. The heavier fractions move to the bottom and the lighter ones to the top. They are then vapourized and collected on the top of the distillation tower in increasing boiling temperature.