Fuels and Earth Science

Question 1

what are hydrocarbons?

Answer 1

compounds which contain carbon and hydrogen only

Question 2

what is crude oil?

Answer 2

• complex mixture of hydrocarbons
• containing molecules in which carbon atoms are in chains or rings
• important source of useful substance i.e. fuels and feedstock
• finate resource
• NEED TO KNOW

Question 3

how can crude oil be separated?

Answer 3

• fractional distillation
• heated until mostly gas (liquid bitumen drained off)
• entre fractional column
• longer hydrocarbons have higher boiling points, so turn back to liquids, drain off
• shorter hydrocarbons drain off later
• separating all the substances

Question 4

what are the 6 fractions of crude oil?

Answer 4

• gas
• petrol
• kerosene
• diesel oil
• fuel oil
• bitumin

Question 5

what are the uses of gas?

Answer 5

heating, cooking

Question 6

what are the uses of petrol?

Answer 6

fuel for cars

Question 7

what are the uses of kerosene?

Answer 7

fuel for aircraft

Question 8

what are the uses of diesel?

Answer 8

fuel for cars and trains

Question 9

what are the uses of fuel oil?

Answer 9

fuel for large ships, and power stations

Question 10

what are the uses of bitumen?

Answer 10

surface roads

Question 11

what are the properties of gases and petrol from crude oil?

Answer 11

• 3 carbons(gases)
• 8 carbons(petrol)
• easy to ignite
• low viscosity(runny)
• low boiling point

Question 12

what are the properties of fuel oil and bitumen from crude oil?

Answer 12

• 40 carbons(fuel oil)
• 70+ carbons(bitumin)
• hard to ignite
• high boiling points
• high viscosity(treacle)

Question 13

what homologous series are most of the fractions part of?

Answer 13

alkana homologous series

Question 14

what is the equation for the molecular formula of the the compounds in the homologous series?

Answer 14

CH2
i.e. Ch4
and C2H6

Question 15

what are the first 2 elements In the homologues series?

Answer 15

methane then ethane

Question 16

how do the boiling points go down the homologous series?

Answer 16

they go up down the group

Question 17

all the homologous series have…

Answer 17

similar chemical properties

Question 18

what is the equation for complete combustion?

Answer 18

hydrocarbon + oxygen = carbondioxide + water

-energy given out

Question 19

when do you get incomplete combustion?

Answer 19

when theres no enough oxygen so produces carbon and carbon monoxide

Question 20

how does carbon monoxide behave as a toxic gas?

Answer 20

• combine with red blood cells and stop blood from carrying oxygen
• stops blooding going to brain, death, coma

Question 21

what are the problems with incomplete combustion forming carbon?

Answer 21

• falls forms soot

- makes buildings look dirty, reduces air quality, worse respiratory problems

Question 22

what are the problems with sulphur dioxide?

Answer 22

• mixes with clouds and form dilute sulfuric acid, acid rain
• lakes become acidic, animals die
• kills trees, damages limestone

Question 23

when fuels are burnt in engines how are pollutants formed?

Answer 23

• oxygen and nitrogen recact at high temperatures to produce oxides of nitrogen
• smog, air pollution

Question 24

advantages of using hydrogen rather then petrol in cars?

Answer 24

• clean fuel
• only water as waste product
• renewable resource

Question 25

disadvantages of using hydrogen rather then petrol in cars?

Answer 25

• special, expensive engine
• expensive to manufacture hydrogen gas
• hard to store hydrogen

Question 26

what are the non renewable energy sources in crude oil and natural gas?

Answer 26

crude oil- petrol, kerosene, diesel oil

natural gas- fossil fuels

Question 27

what is cracking?

Answer 27

turns long saturated alkane molecules into smaller unsaturated alkene and alkane molecules which are more useful

Question 28

why are molecules needed to be cracked into smaller ones?

Answer 28

-more demand for products like petrol and diesel than for bitumen