Fuels

Question 1

What are hydrocarbons

Answer 1

Compounds containing hydrogen and carbon only

Question 2

What are the six useful compounds that can be separated from crude oil called

Answer 2

Gases 
Petrol 
Kerosene 
Diesel oil 
Fuel oil
Bitumen

Question 3

How are the many useful compounds in crude oil separated

Answer 3

Fractional distillation

Question 4

What is crude oil

Answer 4

A FINITE RESOURCE which is FOUND IN ROCK, produced from the REMAINS OF ANCIENT BIOMASS. It is a complex mixture of HYDROCARBONS and the molecules are ARRANGED IN CHAINS OR RINGS

Question 5

How can crude oil be separated by fractional distillation

Answer 5

Because the hydrocarbons have different boiling points

Question 6

What is used to separate crude oil into fractions

Answer 6

A FRACTIONATING COLUMN- a tall column in which the temperature decreases from bottom to top

Question 7

What is it called when hydrocarbons have no double bonds

Answer 7

Saturated

Question 8

What is a homologous series

Answer 8

A family of compounds with SIMILAR CHEMICAL PROPERTIES and GRADUAL VARIATION IN PHYSICAL PROPERTIES.
They have the SAME GENERAL FORMULA with successive members DEFERRING IN MOLECULAR FORMULA BY CH2

Question 9

What is the general formula of an alkane

Answer 9

Cn H(2n+2)

Question 10

What is complete combustion

Answer 10

When hydrocarbons burn in excess air to produce carbon dioxide and water ONLY

Question 11

What is an oxidation reaction

Answer 11

When the hydrocarbons react with the oxygen in the air

Question 12

What is the generic equation for complete combustion

Answer 12

Hydrocarbon + oxygen ————>carbon dioxide + water

Question 13

When balancing an equation what order should you balance the elements

Answer 13

Carbon then…
Hydrogen then…
Oxygen

(Never change the little numbers)

Question 14

Give the generic equation for incomplete combustion

Answer 14

Hydrocarbon + oxygen ————>carbon + carbon monoxide + carbon dioxide + water

Question 15

What is INCOMPLETE combustion

Answer 15

Occurs when there is a limited supply oxygen

Water is still produced but carbon and carbon monoxide are formed as well as carbon dioxide

Question 16

The greater the number of carbon atoms in a molecule…..

Answer 16

The greater the boiling point

Question 17

The bigger the molecule…

Answer 17

The stronger the intermolecular forces

Question 18

Give a use of GASES (a fraction from crude oil)

Answer 18

Domestic heating and cooking

Question 19

Give a use of PETROL (a fraction from crude oil)

Answer 19

Fuel for cars

Question 20

Give a use of KEROSENE (a fraction from crude oil)

Answer 20

Fuel for aircraft

Question 21

Give a use of DIESEL OIL (a fraction from crude oil)

Answer 21

Fuel for some cars and trains

Question 22

Give a use of FUEL OIL (a fraction from crude oil)

Answer 22

Fuel for large ships and power stations

Question 23

Give a use of BITUMEN (a fraction from crude oil)

Answer 23

Surfacing roads and roofs

Question 24

What is the test for the presence of an alkene

Answer 24

Bromine water:
If an alkene ISN’T present it stays orange
If an alkene IS present it goes colourless

Question 25

What is the order of the alkanes

Answer 25

Methane Ethane Propane Butane

Question 26

What is cracking

Answer 26

The breaking down of longer chain hydrocarbons into shorter chain hydrocarbons

Question 27

Are ALKANES saturated or unsaturated

Answer 27

Saturated and covalent

Question 28

Are ALKENES saturated or unsaturated

Answer 28

Unsaturated and covalent

Question 29

Describe the trend in number of atoms in molecules from GASES TO BITUMEN

Answer 29

Increases 

Question 30

Describe the trend in boiling point from GASES TO BITUMEN

Answer 30

Increases

Question 31

Describe the trend in ease of ignition from GASES TO BITUMEN

Answer 31

Becomes more difficult to ignite

Question 32

Describe the trend in viscosity from GASES TO BITUMEN

Answer 32

Viscosity increases (flows with more difficulty)

Question 33

What is the general formula of an ALKENE

Answer 33

CnH(2n)

Question 34

Describe the trend in chain length from GASES TO BITUMEN

Answer 34

Chain length increases

Question 35

What are the advantages of petrol as a vehicle fuel

Answer 35

Easily stored Easily ignited Combustion releases large amounts of energy

Question 36

What are the advantages of hydrogen as a vehicle fuel

Answer 36

Environmental benefits | Easily ignited

Question 37

What are the disadvantages of petrol as a vehicle fuel

Answer 37

High demand | Greenhouse gas

Question 38

What are the disadvantages of hydrogen as a vehicle fuel

Answer 38

Difficult to store in large amounts as it has to be compressed

Question 39

How does cracking work

Answer 39

Cracking involves breaking covalent bonds in hydrocarbon molecules. Crude oil fractions are heated to evaporate them. The vapours are passed over a catalyst containing aluminium oxide and heated to about 650°C Smaller more useful hydrocarbon molecules form and these can be used as fuel or for making polymers

Question 40

What is the functional group of Alcohols

Answer 40

O-H

Question 41

What do the names of alcohols always end in

Answer 41

-anol

Question 42

What are the two methods in which ethanol can be produced

Answer 42

Fermentation & hydration

Question 43

What chemical substance do alcohols contain

Answer 43

Ethanol

Question 44

What is the formula for ethanol

Answer 44

C(2) H(5) OH

Question 45

How is ethanol created through the process of fermentation

Answer 45

Plant material containing sugars is mixed with water and yeast. Enzymes in the yeast turn the sugars into ethanol and carbon dioxide

Question 46

What is the general equation for the production of ethanol through the process of fermentation

Answer 46

glucose ——-> ethanol + carbon dioxide

Question 47

What process increases the concentration of alcohol in a solution

Answer 47

Fractional distillation

Question 48

Explain why the pH and temperature must be controlled carefully in the fermentation tank

Answer 48

It is important because the liquid needs to be at optimum temperature for enzymes to work and so does the pH

Question 49

What are the pros of fermentation

Answer 49

Renewable Only needs to be heated to 37°C 

Question 50

What are the cons of fermentation

Answer 50

Produces CO2 Slow reaction A lot of workers needed

Question 51

What are the pros of the method of hydration in producing ethanol

Answer 51

Only ethanol is produced (no waste products’ | Few workers

Question 52

What are the cons of the process of hydration

Answer 52

Non-renewable - cracked from crude oil Requires more energy - steam (needs to be heated to 100° C)