fuels

Question 1

what are hydrocarbons

Answer 1

Hydrocarbons​ ​are​ ​compounds​ ​that​ ​contain​ ​carbon​ ​and​ ​hydrogen​ ​only

Question 2

what is crude oil

Answer 2

A​ ​complex​ ​mixture​ ​of​ ​hydrocarbons ontaining​ ​molecules​ ​in​ ​which​ ​carbon​ ​atoms​ ​are​ ​in​ ​chains​ ​or​ ​rings​

Question 3

why is crude oil valuable

Answer 3

An​ ​important​ ​source​ ​of​ ​useful​ ​substances (fuel and feedstock for the petrochemical industry)

Question 4

what type of fuel is crude oil

Answer 4

a finite fossil fuel

Question 5

what does “finite” mean

Answer 5

a limited about. (opposite of infinite)

Question 6

what is a “fossil fuel”

Answer 6

fossil fuels are made from the remains od dead animals and plants, formed over thousands of years.

Question 7

what is bad about fossil fuels

Answer 7

fossil fuels take a long time to form, and rhe overuse of fossil fuels globally today, guarantees that fossil fuels will run out within the near future

Question 8

how is crude oil separated

Answer 8

fractional distillation

Question 9

how does fractional distillation work

Answer 9

fractional distillation relies on the different melting and boiling points of the fractions.

Question 10

what is the orocess of fractional distillation for crude oil

Answer 10

The​ ​crude​ ​oil​ ​is​ ​heated​ ​in​ ​the​ ​fractionating​ ​column​ ​and​ ​the​ ​oil​ ​evaporates​ ​and
condenses​ ​at​ ​a​ ​number​ ​of​ ​different​ ​temperatures. The​ ​vaporised​ ​oil​ ​rises​ ​up​ ​the​ ​column​ ​and​ ​the​ ​various​ ​fractions​ ​are
constantly​ ​tapped​ ​off​ ​at​ ​the​ ​different​ ​levels​ ​where​ ​they​ ​condense

Question 11

what is the use of gases

Answer 11

domestic​ ​heating​ ​and​ ​cooking

Question 12

what is the use of petrol

Answer 12

fuel for cars

Question 13

what is the use of kerosene

Answer 13

fuel for aircrafts

Question 14

what is the use of diesel oil

Answer 14

fuel for some cars and trains

Question 15

what is the use of fuel oil

Answer 15

fuel​ ​for​ ​large​ ​ships​ ​and​ ​in​ ​some​ ​power​ ​stations

Question 16

what is the use of bitumen

Answer 16

surface roads and roofs

Question 17

how do hydrocarbon differ

Answer 17

Some​ ​properties​ ​of​ ​hydrocarbons​ ​depend​ ​on​ ​the​ ​size​ ​of​ ​their​ ​molecules.​ ​These properties​ ​influence​ ​their​ ​use​ ​as​ ​fuels

Question 18

what does “viscous”

Answer 18

viscous is the runniness of the substance. less viscous means more runny

Question 19

how does the length of the molecules effect the viscousity

Answer 19

Shorter​ ​the​ ​molecules,​ ​the​ ​less​ ​viscous​ ​it​ ​is​,and​ ​the​ ​longer​ ​the molecules,​ ​the​ ​more​ ​viscous​ ​it​ ​is.

Question 20

how does the length of the molecules effect the boiling point

Answer 20

The​ ​shorter​ ​the​ ​molecules,​ ​the​ ​lower​ ​the​ ​temperature​ ​at​ ​which​ ​that​ ​fraction evaporates​ ​or​ ​condenses​ ​–​ ​and​ ​the​ ​lower​ ​its​ ​boiling​ ​point

Question 21

how does the length of the molecules effect its flammability

Answer 21

The​ ​shorter​ ​the​ ​molecules​ ​–​ ​the​ ​more​ ​flammable​ ​it​ ​is,​ ​so​ ​the​ ​easier​ ​it​ ​is​ ​to​ ​ignite

Question 22

what are oroducts of complete combustion of hydrocarbon fuels

Answer 22

CO2​ ​​ ​and​ ​H​2O​ ​ ​are​ ​produced

Question 23

what is incomplete combustion

Answer 23

If​ ​there’s​ ​not​ ​enough​ ​oxygen,​ ​some​ ​of​ ​the​ ​fuel​ ​doesn’t​ ​burn​ ​–​ ​this​ ​is​ ​partial combustion.​

Question 24

what are products of incomplete combustion

Answer 24

solid​ ​particles​ ​of​ ​soot​ ​(carbons)​ ​and​ ​unburnt​ ​fuel​ ​are released as well as carbon​ ​monoxide​ ​(CO)​ ​​ ​when​ ​there​ ​isn’t​ ​enough​ ​oxygen​ ​to produce​ ​CO2​ ​​ ​instead

Question 25

how is carbon monoxide a toxic gas

Answer 25

carbon​ ​monoxide​ ​is​ ​a​ ​colourless​ ​and​ ​odourless​ ​gas​ ​which,​ ​if​ ​breathed​ ​in,
prevents​ ​red​ ​blood​ ​cells​ ​carrying​ ​oxygen​ ​around​ ​your​ ​body,​ ​which​ ​leads​ ​to​ ​death

Question 26

what does soot cause in appliances that use carbon compounds as fuels

Answer 26

soot causes global dimming

Question 27

how do impurities in some hydrocarbon fuels result in the production​ ​of​ ​sulfur​ ​dioxide

Answer 27

Most​ ​fuels,​ ​including​ ​coal,​ ​contain​ ​carbon​ ​and/or​ ​hydrogen​ ​and​ ​may​ ​also contain​ ​some​ ​sulfur and when​ ​the​ ​fuels​ ​are​ ​burnt​ ​in​ ​oxygen,​ ​this​ ​sulfur​ ​can​ ​react​ ​to​ ​form​ ​sulfur dioxide

Question 28

what are some problems of acid rain

Answer 28

• Damages​ ​buildings​ ​and​ ​statues​ ​(made​ ​of​ ​limestone)
• Reduce​ ​the​ ​growth​ ​of​ ​or​ ​kill​ ​trees​ ​and​ ​crops
• Lower​ ​pH​ ​of​ ​water​ ​in​ ​lakes,​ ​killing​ ​fish

Question 29

what is acid rain caused by

Answer 29

acid rain is caused when sulfur dioxide dissolves in rain water

Question 30

why can fuels burned at high temperatures react togetehr to produce oxides

Answer 30

• Nitrogen​ ​and​ ​oxygen​ ​from​ ​the​ ​air​ ​combine​ ​to​ ​produce​ ​nitrogen​ ​monoxide
• when​ ​this​ ​nitrogen​ ​monoxide​ ​is​ ​released​ ​from​ ​vehicle​ ​exhaust​ ​systems,​ ​it combines​ ​with​ ​oxygen​ ​in​ ​the​ ​air​ ​to​ ​form​ ​nitrogen​ ​dioxide
• nitrogen​ ​monoxide​ ​and​ ​nitrogen​ ​dioxide​ ​are​ ​pollutants

Question 31

what are the advantages of using hydrogen as fuel

Answer 31

• Use​ ​of​ ​hydrogen​ ​–​ ​petrol​ ​is​ ​from​ ​crude​ ​oil,​ ​a​ ​finite​ ​resource
• Only​ ​produces​ ​water​ ​–​ ​no​ ​CO2​ ​​ ​produced​ ​which​ ​contributes​ ​to​ ​global
  warming

Question 32

what are disadvantages of using hydrogen as fuel

Answer 32

• Expensive
• Difficult​ ​to​ ​transport​ ​and​ ​store​ ​hydrogen
• Dangerous​ ​–​ ​hydrogen​ ​can​ ​be​ ​explosive

Question 33

what is methane

Answer 33

methane​ ​is​ ​a​ ​non-renewable​ ​fossil​ ​fuel​ ​found​ ​in​ ​natural​ ​gas

Question 34

what is cracking

Answer 34

Hydrocarbons​ ​can​ ​be​ ​cracked​ ​to​ ​produce​ ​smaller,​ ​more​ ​useful​ ​molecules.​ ​This process​ ​involved​ ​heating​ ​the​ ​hydrocarbons​ ​to​ ​vaporise​ ​them.

Question 35

why is cracking necessary

Answer 35

Demand​ ​for​ ​smaller​ ​chained​ ​alkanes​ ​is​ ​much​ ​greater​ ​than​ ​that​ ​for​ ​longer​ ​chained alkanes and shorter​ ​chained​ ​hydrocarbons​ ​ignite​ ​more​ ​easily​ ​and​ ​so​ ​are​ ​more​ ​useful​ ​as​ ​fuels