Carbon Compounds as fuels and feedstock

Question 1

What are hydrocarbons?

Answer 1

Compounds that only contain hydrogen and carbon atoms only

Question 2

Where does crude oil come from?

Answer 2

Formed over millions of years from the fossilised remains of plankton
Found in porous rocks in the Earth’s crust
A finite (non-renewable) resource

Question 3

What is crude oil?

Answer 3

A mixture of hydrocarbons existing in liquid phase in natural underground resources
Most are alkanes

Question 4

What is the general formula for alkanes?

Answer 4

CnH2n+2

Question 5

What are the first four alkanes?

Answer 5

Methane
Ethane
Propane
Butane

Question 6

How do you separate the hydrocarbons in crude oil?

Answer 6

Fractional distillation

Question 7

How does fractional distillation work?

Answer 7

Heated crude oil enters the fractionating column
Vapours rise through the column and condense when cool enough
But because of different boiling points
Small hydrocarbons with weak intermolecular forces leave as gases
Long hydrocarbons with stronger intermolecular forces leave as liquids