Topic 5 - Fuels

Question 1

what is crude oil?

Answer 1

crude oil is a mixture of hydrocarbons

Question 2

what are hydrocarbons?

Answer 2

hydrocarbons are compounds containing only hydrogen and carbon

Question 3

what is the name of the method used to separate hydrocarbons/ crude oil?

Answer 3

fractional distillation

Question 4

where does fractional distillation of crude oil take place?

Answer 4

in a fractionating column

Question 5

as the hydrocarbons get larger (the greater number of carbon atoms in a molecule) they become…

Answer 5

• more viscous
• less flammable
• less volatile
• have a higher boiling point

Question 6

what are refinery gases?

Answer 6

e.g. liquified petroleum gas, propane and butane for bottled gases

Question 7

what is gasoline (petrol) used for?

Answer 7

fuel for cars

Question 8

what is kerosene (paraffin) used for?

Answer 8

fuel for jet aircrafts

Question 9

what is diesel oil (gas oil) used for?

Answer 9

fuel for cars and large vehicles

Question 10

what is fuel oil used for?

Answer 10

generating electricity and in marine diesel engines

Question 11

what is bitumen used for?

Answer 11

to make roads

Question 12

is bitumen a long or short chain hydrocarbon?

Answer 12

long-chain hydrocarbon

Question 13

is petrol a long or short chain hydrocarbon?

Answer 13

short-chain hydrocarbon

Question 14

what is a fuel?

Answer 14

a fuel is a substance that releases useful amounts of energy when burned

Question 15

when a fuel burns, it reacts with ________ in the air.

what is the missing word?

Answer 15

oxygen

Question 16

what is complete combustion?

Answer 16

complete combustion is when a hydrocarbon burns with substantial amounts of oxygen, meaning carbon dioxide and water are produced, and energy is released.

Question 17

what is incomplete combustion?

Answer 17

incomplete combustion is when a hydrocarbon burns with insufficient amounts of oxygen, meaning carbon monoxide and water are produced.

Question 18

what is (extreme) incomplete combustion?

Answer 18

(extreme) incomplete combustion is when a hydrocarbon burns with very little oxygen, and therefore carbon, a solid, is produced as well as water.

Question 19

what is carbon monoxide?

Answer 19

carbon monoxide is a toxic, colourless and odourless gas that combines irreversibly with the haemoglobin in red blood cells, reducing their oxygen-carrying ability, which eventually results in death by lack of oxygen

Question 20

what are some of the problems associated with acid rain?

Answer 20

1. damage to:
   - plants
   - animals
   - buildings
   - metals
2. increase in acidity levels of lakes and rivers, which can be harmful to organisms living in them

Question 21

what is global warming?

Answer 21

global warming is the gradual increase in temperature of the Earth’s atmosphere

Question 22

why is the surface of the Earth warmer than it would be without the gases: 
-carbon dioxide
-methane
-water vapour
in the atmosphere?

Answer 22

because these gases in the atmosphere absorb heat and radiate it back down to Earth

Question 23

what is iron-seeding?

Answer 23

iron-seeding is a process of removing carbon dioxide from the atmosphere:

• iron dust is added to oceans
• this enhances the growth of plankton, which takes in carbon dioxide
• this therefore reduces the amount of carbon dioxide in the atmosphere

Question 24

how can chemists convert carbon dioxide into a simple hydrocarbon?

Answer 24

by using a catalyst

Question 25

what is the name of substances that are becoming an attractive alternative to fossil fuels?

Answer 25

biofuels

Question 26

what are biofuels based on?

Answer 26

sustainable resources such as wood and alcohol from plants

Question 27

what is ethanol?

Answer 27

ethanol is an alcohol produced by the fermentation of sugar beet and sugar cane.

Question 28

what is ethanol used for?

Answer 28

- as a fuel in its purest form | - added to petrol to reduce the need for petrol and to improve vehicle emissions

Question 29

what is a disadvantage to using ethanol?

Answer 29

large areas of fertile land are needed to grow the crops (sugar beet and sugar cane)

Question 30

what is a fuel cell?

Answer 30

a fuel cell is a way of producing and harnessing energy from a chemical reaction

Question 31

what is the cleanest of all the fuels, and why?

Answer 31

hydrogen, because it only produces water in a fuel cell

Question 32

what are the main factors of a good fuel?

Answer 32

- safe to transport/ does not catch alight easily - easy to transport and store - good provider of heat energy - clean fuel that produces little or no toxic or polluting products

Question 33

how can the amount of energy released by the combustion of different fuels be compared?

Answer 33

by measuring the temperature rise of a fixed volume of water as it is heated by a known amount of a certain fuel

Question 34

What are the advantages and disadvantages of using biogas like bio methane as an alternative to fossil fuels?

Answer 34

``` Advantages - Renewable, sustainable Easy to replace crops use to produce biogas quickly Carbon neutral Clean fuel with few pollutants released Cheap ``` Disadvantages - Less land to grow food for people who need it Large storage space need to store the gas Transport

Question 35

What are the advantages and disadvantages of using bioethanol?

Answer 35

Advantages - Less crude oil use Carbon neutral Clean fuel few pollutants released Disadvantages - Less land to grow food Requires suitable climate Distillation needed after produced

Question 36

Advantages and disadvantages of hydrogen fuel cells?

Answer 36

Advantages- No pollutants No recharging required Very efficient, not a lot of energy wasted ``` Disadvantages - Storage space needed explosive gas Energy needed to use electrolysis which requires energy Expensive (electrolysis) ```

Question 37

How do you measure the energy content in fuels?

Answer 37

Colorimetric method

Question 38

Describe the experiment in which you can measure the energy content of fuels?

Answer 38

``` Weigh fuel Fixed volume of water in beaker Set up draft shield Light fuel and heat water by 10 degrees Re-weigh fuel Calculate mass difference Repeat with another fuel (replace water) ```

Question 39

What is cracking?

Answer 39

A thermal decomposition react that breaks down long chain alkanes into smaller, more useful alkanes and alkenes

Question 40

What does cracking require in order to break down a hydrocarbon?

Answer 40

Heat & a catalyst

Question 41

Examples of natural polymers?

Answer 41

Starch (formed from glucose) and protein (formed from amino acids)

Question 42

What is a monomer?

Answer 42

A monomer is a short-chain unsaturated hydrocarbon molecule.

Question 43

What are the properties of poly(ethene) and what are its uses?

Answer 43

Properties- Good chemical resistance, light, flexible Uses - Food coverings, plastic bags, hose and water pipes

Question 44

What are the properties and uses of poly(propene)?

Answer 44

Properties- Flexible, tough, good chemical resistance Uses - Ropes, chairs, stationary, crates

Question 45

What are the properties and uses of poly(chloroethene) PVC?

Answer 45

Properties - Water-resistant, flexible or rigid Uses - Clothing, double-glazed window frames, electrical components, pipes

Question 46

what are the uses and properties of poly(tetraflouroethene) , PTFE?

Answer 46

Properties - Water and flame resistant, flexible, durable, unreactive Uses - non-stick cookware coating, waterproof coatings

Question 47

Why are plastics/polymers hard to dispose of?

Answer 47

- non-biodegradable so remain in landfill sites taking up space - burning them releases pollutants/toxic gases - only some plastics can be recycled

Question 48

What properties make a good fuel?

Answer 48

Ease of ignition Energy produced Waste gases pollutants given off Storage and transport easy?

Question 49

What environmental effect does sulfur dioxide have?

Answer 49

Dissolves easily in water, contributing to acid rain which causes damage to lakes, rivers, houses, farms, buildings

Question 49

Why are people concerned with the level of carbon dioxide in the atmosphere?

Answer 49

Carbon dioxide is a greenhouse gas, meaning that it traps heat in the atmosphere and radiates it back down to earth.