Crude Oil and Fuels

Question 1

What does crude oil contain?

Answer 1

Different compounds that boil at different temperatures and need to separate to be made useful.

Question 2

How can we separate a mixture of liquids?

Answer 2

Through distillation

Each compound boiled is called a fraction

Question 3

What is the general formula of the hydrocarbon : alkanes? And are they saturated or unsaturated hydrocarbons?

Answer 3

C n H 2n+2

Saturated

Question 4

What is fractional distillation?

Answer 4

Separates the compounds in a hydrocarbon at different boiling points.

The larger the molecule the higher the boiling point

Question 5

Explain the fractional distillation column

Answer 5

Crude oil is vaporised and fed into the bottom of the column.
Hot at the bottom, cold at the top
From bottom to top:
Residue, diesel, kerosene, petrol, petroleum
Temp at bottom is 350 degrees
Temp at top is 50 degrees

Question 6

Fractions with low boiling points have what properties?

Answer 6

Low boiling range
Low viscosity (runny)
Flammable
Little smoke, useful as fuels

Question 7

When pure hydrocarbons are burnt completely what product are formed?

Answer 7

Oxidised to carbon dioxide and water

Question 8

What might form from incomplete combustion and what is it?

Answer 8

Carbon monoxide (causes global dimming and is poisonous) and carbon particulates
When there's a limited supply of air

Question 9

What causes acid rain?

Answer 9

Sulphur dioxide and nitrogen oxides

A product of burning fossil fuels

Question 10

What two methods are used to remove the amount of sulfur dioxide produced by burning fuels?

Answer 10

Sulfur removed from fuels before sent for purchase

Exhausts in cars have catalytic convertors that remove carbon monoxide and nitrogen oxide

Question 11

What is the equation for carbon monoxide

Answer 11

CO

Question 12

What are biofuels

Answer 12

Fuels made from plant and animal product and are renewable. Biodiesel is made from vegetable is extracted from plants.

Question 13

Give advantages and disadvantages of biodiesel?

Answer 13

A : Little contribution to CO2 levels

D : Large areas of farmland to grow the biodiesel

Question 14

What is ethanol

Answer 14

Made from sugar cane/beet
Biofuel
Can be mixed with petrol

Question 15

Give one advantage and one disadvantage of using hydrogen as fuel

Answer 15

A : Only produces water when burnt

D : Difficult to store

Question 16

How do you create hydrogen?

Answer 16

Produced from water by electrolysis but this requires large amount of energy.