fuels and energy from fuels

Question 1

fossil fuel

Answer 1

a natural fuel that is formed in the earth from plant or animal remains

Question 2

coal

Answer 2

combustible fossil fuel formed from partial decay of plant matter

Question 3

petrodiesel

Answer 3

liquid hydrocarbon fossil fuel obtained from crude oil

Question 4

greenhouse gas

Answer 4

process of warming the earths lower atmosphere due to the increase emmissions of gases in the air

Question 5

fuel

Answer 5

a substance that burns in air or oxygen to produce a useable amount of energy

Question 6

fossil fuel examples

Answer 6

methane, CSG, liquid petroleum gas, diesel, petrodiesel

Question 7

biofuel examples

Answer 7

biodiesel, bioethanol, biogas

Question 8

safety implication of fuels

Answer 8

because fuels have low BP low flashpoint and high flammability then easily combust - must ensure it is a well ventilated area, safety equipment including extinguisher and fire blankets , away from naked flames

Question 9

bonding and properties

Answer 9

structure - bonding intermolecular- properties -uses

• properties take into account of size of molecule and type in intermolecular bonds - increase size increase dispersion forces

Question 10

flashpoint

Answer 10

temperature at which a particular organic compound gives off sufficient vapour to ignite in air - smaller hydrocarbons have weaker interm. bonds and have lower flashpoints and are more flammable

Question 11

flammability

Answer 11

a flammable liquid is any liquid with a flashpoint below 37.8 celsius - ignite and burn easily at lower temps - vaporisation rate increases as temp increases

Question 12

renewable fuels

Answer 12

they are fuels which can be replenished at a similar rate to which they are consumed - often involves breakdown of plant and animal materials
-can be grown quickly and harnessed as fuel
-eg - biogas biodiesel and bioethanol

Question 13

non renewable fuels

Answer 13

fueal that are not replenished and used at similar rates –> finite / limited
-eg - methane , fossil fuels etc.

Question 14

renewable energy sources

Answer 14

produced faster than used
- eg solar energy , hydro electricity, tidal and wave power, wind turbines , biofuels etc.

Question 15

non renewable energy sources

Answer 15

those used up faster than they are produced
- eg nuclear energy stores and fossil fuels

Question 16

biofuels

Answer 16

• made from plant matter –> renewable
• biogas, biodiesel and bioethanol

Question 17

how are biofuels relatively carbon neutral?

Answer 17

plants will undergo photosynthesis and they will absorb the carbon dioxide from atmosphere - the plant matter is converted to biofuel and undergoes combustion - this reduces CO2 net emissions and has a more positive impact on the environment.

Question 18

biogas

Answer 18

a mixture of gases produced by breakdown of organic matter ( algae, crops, wood etc)
- broken down by bacteria into the gas (anaerobic)

Question 19

biogas process of production

Answer 19

natural breakdown - funnel roof placed above decomposing materials and piped the biogas into the storage (basic production)

Question 20

via digester biogas

Answer 20

structured apparatus with cylinder containing plant material - more controlled , efficient, less emissions + more expensive to maintain

Question 21

bioethanol

Answer 21

produced by the fermentation of glucose in organic matter by the mocroorganism yeast (wheat,corn and sugarcane)

Question 22

ethanol production

Answer 22

glucose –> (bacteria over the arrow) ethanol + carbon dioxide

Question 23

biodiesel

Answer 23

produced by esterification of fats from animal products and oils from crops ( include canola and palm oil etc. which contain tiglycerides)
- the tri. have 3 fatty acids and a glycerol joint with an ester link
- producing biodiesel from triglycerides and alcohol (often methanol) will be in a tranesterifcation reaction to form methyl ester and glycerol

Question 24

biodiesel being produced by fatty acids

Answer 24

fatty acid + methanol -> fatty acid methyl estert ( biodiesel) + water

Question 25

how to tell a molecule is a component of biodiesel

Answer 25

methyl group joined by the ester link

Question 26

energy calculation

Answer 26

E =n times delta H

Question 27

LPG advantage and disadvantage

Answer 27

• • low costs, easily separated, relatively high energy content
• _ non renewable and polluting

Question 28

petrol pros and cons

Answer 28

+ high energy content and ease of transport
- non renewable , polluting and limited reserves

Question 29

coal pros and cons

Answer 29

+ large reserves and high energy content
- non renewable , large emissions, hard to transport

Question 30

natural gas pros and cons

Answer 30

+ more efficient than coal for electricity, easy to transport , high energy content
- polluing less than coal and petrol , nonrenewable , limited

Question 31

main functional group in biodiesel

Answer 31

methyl ester

Question 32

biodiesel vs petrodiesel

Answer 32

biodiesel - higher visocsity , more hygroscopic , renewable , produces less energy, higher MP, lower net emissions , biodegradable, requires land and water
- opposites for petrodiesel

Question 33

hygroscopic

Answer 33

the ability to absorb water