5.8 Recall the names and uses of the main fractions obtained from crude oil: refinery gases, gasoline, kerosene, diesel, fuel oil and bitumen

This diagram has all that you need to know :)

5.7 Describe and explain how the industrial process of fractional distillation separates crude oil into fractions

Crude oil is separated into it's various hydrocarbons by fractional distillation, which happens like so:
1. Crude oil is heated
2. As a gas it floats upwards, where the temperature decreases
3. One by one, each compound in the crude oil will reach it's condensing point and condense
4. It will then be collected

This ensures that all groups with similar condensing temperatures (known as fractions) are each separated, since each fraction is a different substance

5.6 Understand that crude oil is a mixture of hydrocarbons

Basically, crude oil is made up of different hydrocarbons (molecules with ONLY hydrogen and carbon atoms in them)