Section 5 - Organic Chemistry

Question 1

What is crude oil?

Answer 1

A mixture of hydrocarbons, also called petroleum.

Question 2

What process is used to separate crude oil into fractions?

Answer 2

Fractional Distillation

Question 3

Describe the process used to separate crude oil into fractions and include the conditions.

Answer 3

1. The crude oil is vaporised at 350 degrees Celsius.
2. The crude oil, now vaporised, is placed in the fractionating column and it rises - as it is hot. (heat rises)
3. As it rises, each hydrocarbon cools reaches their respective boiling points, condensing as soon as they do.
4. Each fraction will have a different hydrocarbon ready for collection.

Question 4

Name each fraction of the fractionating column.

Answer 4

LPG (Liquefied Petroleum Gases)
Petrol
Naphtha
Kerosene
Gas Oil (diesel)
Mineral Oil
Fuel Oil
Wax
Bitumen

Question 5

How many different types of cracking are there?

Answer 5

2

Question 6

Describe each type of cracking.

Answer 6

Thermal - 1000 degrees Celsius, 70 atm and produces lots of alkenes.

Catalytic - 450 degrees Celsius, slight pressure, Zeolite catalyst, produces motor fuels and aromatic hydrocarbons. Less expensive - lower temperature, lower pressure and catalyst speeds up reaction, saving time.

Question 7

What is the test for OH- ions?

Answer 7

React with PCl5 –> Misty fumes of HCl gas will be produced if OH ions are present.