8.1-8.16 Fuel and Earth Science

Question 1

What are hydrocarbons?

Answer 1

Compounds that contain hydrogen and Carbon ONLY

Question 2

What is crude oil?

Answer 2

.A complex mixture of hydrocarbons

Question 3

In Hydrocarbons how are the molecules situated?

Answer 3

In chains or rings

Question 4

Is crude oil infinite or finite?

Answer 4

Finite

Question 5

How does turning crude oil into useful mixtures by fractional distillation work?

Answer 5

.Each hydrocarbon has a different boiling point
.The crude oil is heated in the fractionating column and the oil evaporates and condenses at a number of different temperatures
.The fractionating column works continuously
.Heated crude oil is piped in at the bottom, the vapours rise up the column and vapourised fractions are tapped off at different heights
.The fractions can be processed to produce fuels and feedstock

Question 6

What are the gases used for?

Answer 6

Domestic heating and cooking

Question 7

What is petrol used for?

Answer 7

Fuel for cars

Question 8

What is kerosene used for?

Answer 8

Fuel for aircraft

Question 9

What is diesel oil used for?

Answer 9

Fuel for some cars and trains

Question 10

What is fuel oil used for?

Answer 10

Fuel for large ships and in some power stations

Question 11

What is bitumen used for?

Answer 11

Surface roads and roofs

Question 12

Give three ways the hydrocarbons in each fraction differ from eachother

Answer 12

.The number of hydrogen and carbon atoms they contain
.Different boiling points
.Ease of ignition differs
.Viscosity differs

Question 13

What is a homologous series?

Answer 13

A series of compounds that have similar properties

Question 14

Give three similar properties a homologous series has

Answer 14

.Same general formula
.Similar physical properties
.Similar chemical properties

Question 15

What is given out in the combustion of hydrocarbon fuels?

Answer 15

Energy

Question 16

What is produced in the complete combustion of hydrocarbons?

Answer 16

Carbon dioxide and water

Question 17

Why can the incomplete production of hydrocarbons produce carbon and carbon monoxide?

Answer 17

.If there is not enough oxygen some of the fuel doesn’t burn (Partial combustion)-Solid particles of carbon (soot) is released
.Carbon monoxide is released when there isnt enough oxygen to produce CO2 instead

Question 18

Explain how carbon monoxide behaves as a toxic gas

Answer 18

.It is colourless and odourless gas which if inhaled binds to the haemoglobin preventing red blood cells from carrying oxygen around the body leading to death

Question 19

What are the two problems caused by incomplete combustion producing carbon monoxide and soot?

Answer 19

.Carbon monoxide causes health problems

.Soot causes global dimming

Question 20

How can impurities in hydrocarbons result in the production of sulfur dioxide?

Answer 20

.Most fuels like coal and carbon may also include some sulfur
.When the fuels are burnt in oxygen this can react and form sulfur dioxide

Question 21

Give two problems that are associated with acid rain when sulfur dioxide dissolves in rainwater

Answer 21

.Damages buildings and statues made of limewater
.Reduce the growth of or kill trees or crops
.Lower Ph of water in lakes killing fish

Question 22

What two elements react at high temperatures when fuels are burned in engines?

Answer 22

Nitrogen and Oxygen

Question 23

When burned in engines what do nitrogen and oxygen combine to make?

Answer 23

Nitrogen monoxide

Question 24

When nitrogen oxide is released from exhausts it combines with oxygen to form what?

Answer 24

Nitrogen dioxide

Question 25

Nitrogen monoxide and nitrogen dioxide are examples of what?

Answer 25

Pollutants

Question 26

Give an advantage of using hydrogen as fuel rather than petrol in cars

Answer 26

.Petrol is from crude oil which is a finite resource Hydrogen is infinite .Only produces water- no CO2 produced which contributes to global warming

Question 27

Give a disadvantage of using hydrogen as a fuel instead of petrol

Answer 27

.Expensive .Difficult to transport .Dangerous-hydrogen can be explosive

Question 28

Where is Methane found in?

Answer 28

Natural gas

Question 29

Petrol, Kerosene and Diesel are all examples of what?

Answer 29

Non renewable fossil fuels obtained from crude oil

Question 30

What process can hydrocarbons undergo to produce smaller, more useful molecules?

Answer 30

Cracking

Question 31

What happens to the vapours in cracking?

Answer 31

.Passed over a hot catalyst | .Mixed with steam and heated to a very high temperature so that thermal decomposition reactions can occur

Question 32

What do the products of cracking include?

Answer 32

.Alkanes | .Alkenes (Unsaturated hydrocarbons)

Question 33

Give two reasons why cracking is necessary

Answer 33

.Demand for smaller chain alkanes is much greater than longer chained alkanes .Shorter chain hydrocarbons ignite more easily and so are more useful as fuels