Organic chemistry

Question 1

What does finite mean?

Answer 1

Something that will not last forever.

Question 2

What type of resource is crude oil?

Answer 2

Finite.

Question 3

What is crude oil?

Answer 3

The remains of an ancient biomass (mass of living organisms).

Question 4

Where is crude oil found?

Answer 4

In rocks, both on land and beneath the sea.

Question 5

What is the biomass within crude oil mostly made up of?

Answer 5

Tiny sea creatures called plankton which have died, sunk and been buried in the mud.

Question 6

What happens over millions of years to biomass?

Answer 6

It decays.

Question 7

What do high temperatures and pressures do to biomass?

Answer 7

It turns the biomass into a liquid containing a very large number of compounds.

Question 8

What are most of the compounds in crude oil?

Answer 8

Hydrocarbons - they mostly contain hydrogen and carbon atoms.

Question 9

What is an alkane?

Answer 9

A hydrocarbon that only has single bonds between it’s atoms.

Question 10

Are most of the hydrocarbons in crude oil alkanes or alkenes?

Answer 10

Alkanes.

Question 11

What does homologous mean?

Answer 11

Having the same features.

Question 12

What is the alkane homologous series?

Answer 12

A series of similar hydrocarbon molecules of increasing length. Each hydrocarbon has one more carbon and two more hydrogen than before.

Question 13

What are the first four alkanes with the homologous series?

Answer 13

Methane, ethane, propane and butane.

Question 14

What is the general formula for the alkane homologous series?

Answer 14

C(n)H(2n+2).

Question 15

Why is raw crude oil not useful?

Answer 15

It is a mixture of hydrocarbons of different lengths.

Question 16

What is a fraction?

Answer 16

A smaller part of a whole.

Question 17

What does each fraction in crude oil contain?

Answer 17

Molecules with a similar amount of carbon atoms.

Question 18

What is feedstock?

Answer 18

A raw material that is used for an industrial process.

Question 19

What are petrochemicals?

Answer 19

Chemicals that use crude oil as fractions are called petrochemicals.

Question 20

What are the main fuels that come from petrochemicals?

Answer 20

Petrol, diesel, kerosene, heavy fuel oil and liquefied petroleum gas.

Question 21

What are the main useful materials produced by the petrochemical industry?

Answer 21

Solvents, lubricants, polymers and detergents.

Question 22

How is crude oil separated into its fractions?

Answer 22

Using a process called fractional distillation.

Question 23

How does fractional distillation work?

Answer 23

Crude oil is heated and evaporated - the vapour is passed into the fractioning column.

Question 24

What happens as you go up the fractioning column?

Answer 24

The temperature decreases and fractions with the lower boiling points condense at each level. (hottest at the bottom = highest BP condenses first)

Question 25

What is the order of fractions from top to bottom of the fractioning column?

Answer 25

Gases, petrol, kerosene, diesel, fuel oil, bitumen.

Question 26

What is gas used for?

Answer 26

Heating and cooking.

Question 27

What is petrol used as?

Answer 27

Fuel for cars.

Question 28

What is kerosene used as?

Answer 28

Fuel for aircrafts.

Question 29

What is diesel used as?

Answer 29

Fuel for some cars and trains.

Question 30

What is fuel oil used as?

Answer 30

Fuel for large ships and power stations.

Question 31

What is bitumen used for?

Answer 31

Surfacing roads and roofs.

Question 32

What do the sizes of hydrocarbons determine?

Answer 32

The hydrocarbon's properties.

Question 33

What properties do larger molecules have?

Answer 33

Higher boiling points, a higher viscosity and less flammable.

Question 34

What is viscosity?

Answer 34

How hard something is to pour.

Question 35

What do the properties of hydrocarbons influence?

Answer 35

How hydrocarbons are used as fuels e.g. diesel needs to be heated before it can be set on fire in a diesel engine as it is not very flammable.

Question 36

Why is domestic gas a gas at room temperature?

Answer 36

It has a low boiling point.

Question 37

What can domestic gas easily be used for?

Answer 37

Transporting in pipes to people's homes.

Question 38

What can long chain molecules in crude oil be used for?

Answer 38

Selling.

Question 39

Why do shorter chain molecules in crude oil fetch a higher price?

Answer 39

They are more in demand.

Question 40

What is cracking?

Answer 40

A process where long chain molecules are broken apart to form shorter, more useful molecules.

Question 41

What are the two main methods of cracking?

Answer 41

Steam cracking and catalytic cracking.

Question 42

What happens in catalytic cracking?

Answer 42

Crude oil is vaporised, heated to about 550C and passed over a catalyst containing aluminium oxide.

Question 43

What do catalysts do to cracking?

Answer 43

They speed up the reaction that breaks up larger molecules.

Question 44

What happens in steam cracking?

Answer 44

They use higher temperatures and pressures but no catalysts.

Question 45

What will cracking equations always produce?

Answer 45

One alkane and one alkene.

Question 46

What are alkenes?

Answer 46

Hydrocarbons with double bonds.

Question 47

What does cracking often produce?

Answer 47

Alkenes.

Question 48

Why are alkenes more reactive that alkanes?

Answer 48

The double bonds can come apart to attach to other molecules.

Question 49

What are alkenes used for?

Answer 49

Producing polymers and other useful products.

Question 50

What can alkenes be detected with?

Answer 50

Bromine water - they turn it from an orange colour to colourless; a reaction undergoes in which bromine atoms cause the double bonds to come apart.

Question 51

What is the scientific name for burning?

Answer 51

Combustion.

Question 52

What do fuels use combustion for?

Answer 52

It allows them to transfer energy from the chemical store to the thermal store.

Question 53

What type of process is combustion?

Answer 53

Oxidation.

Question 54

What does the complete combustion of a hydrocarbon produce?

Answer 54

Carbon dioxide and water.