Topic 8- Fuels

Question 1

What is a hydrocarbon

Answer 1

A compound of only hydrogen and carbon

Question 2

What is an alkane?

Answer 2

Saturated hydrocarbon

no double bonds

Question 3

What is an alkene?

Answer 3

Unsaturated hydrocarbon

could have more hydrogen

Question 4

What is complete combustion?

Answer 4

Fuel burns with enough O2 to make water and carbon dioxide

rather than water and carbon monoxide

CO vs CO2

Question 5

What is crude oil?

Answer 5

-A mixture hydrocarbons arranged in chains or rings
-a finite resource
-Used in industry (fuels)

Question 6

What is cracking?

Answer 6

Breaking long chain hydrocarbons into shorter chaines (higher demnd/more useful)
-Produces an alkane
-Produces an alkene

Question 7

What are the first 4 Alkanes?

C2H2n+2

Answer 7

Methane
Ethane
Propane
Butane

then in greek numbers

pentane, hexane, heptane, octane…

Question 8

How is crude oil seperated

Answer 8

Industrial fractional distillation (column)
-Heated and vaporised
-Each column has a lower temperature
-The hydrocarbons will condense at different columns (differentt boiling points)
-And are collected as liquids

Question 9

What are produced as crude oil is fractionally distilated?

Answer 9

-Gas
-Petrol
-Kerosene
-Diesal oil
-Fuel oil
-Bitumen

Question 10

What are gases used for?

Answer 10

-Domestic cooking
-Domestic heating

Question 11

What is petrol used for used for?

Answer 11

-Cars

Question 12

What is kerosene used for?

Answer 12

-Aircrafts

Question 13

What is diesal oil used for?

Answer 13

-Cars and trains

Question 14

What is fuel oil used for?

Answer 14

-Large ships
-Power stations

Question 15

What is bitumen used for?

Answer 15

-Surface roads and roofs

Question 16

Pattern of viscosity?

Answer 16

-Les viscous (shorter chain)
-More viscous (longer chaine

Question 17

Pattern of flammability?

Answer 17

-More flammable (shorter chain)
-Less flammable (longer chain)

Question 18

What is a homologeous series?

Answer 18

-Series have same formula (differ by number of CH2 units)
-Have similar but gradual variation in chemical properties

Question 19

What is formed when hydrocarbons are cobusted?

Answer 19

-Water + CO2
-Realeases energy (exothermic)

Question 20

Why does incomplete combustion produce carbon monoxide?

Answer 20

-Not enough oxygen
-Makes CO bonds rather than CO2

Question 21

How does carbon monoxide behave as a toxic gas

Answer 21

-Binds to heameglobin more easily than oxygen
-Starves body of oxygen

Question 22

What are the problems caused by incomplete combustion of hydrocarbons?

soot and CO

Answer 22

Soot:
-Air pollution
-Breathing problems
Carbon monoxide:
-Greenhouse gas
-Toxic

soot is pure CARBON

Question 23

What do hydrocarbon/ fossil fuel impurities cuase?

Answer 23

acid rain

SULFUR IMPURITIES

Question 24

How do sulfur impurities cuase acid rain?

Answer 24

-Combustion into SO2
-Reacts in clouds (water) into H2SO4
-Which is acid rain

Question 25

What affects does acid rain have?

Answer 25

-Kill animals
-Contaminate water sources
-Erode/corrode buildings

Question 26

What pollution do car fumes form?

Answer 26

-NO and NO2
-Produces activation energy allowing Nitrogen and Oxygen to react

Question 27

What are the effects of NO and NO2?

Answer 27

-Greenhouse gas

Question 28

Advantages of using hydrogen as fuel?

Answer 28

-Renewable
-Does not create polllutants
-Releases more energy (than petrol)

Question 29

Disadvantages of using hydrogen as fuel?

Answer 29

-Needs electrolysis to break from water (expensive + time consuming)
-Needs storing in special engine (highly flammable)

Question 30

What is cracking of hydrocarbons?

Answer 30

-Breaking larger saturated alkanes into
-Smaller unsaturated Alkanes
-And alkene

Question 31

Why is cracking necessary?

Answer 31

-Production of more useful shorter hydrocarbon molecules§