CC16 Fuels

Question 1

What is crude oil?

Answer 1

A mixture of hydrocarbons

Question 2

What is crude oil formed from?

Answer 2

The remains of ancient biomass (mostly plankton) that was buried in mud

Question 3

What is a finite resource? Why is crude oil a finite resource?

Answer 3

One that will run out. Because it takes longer to form than the rate at which we are using it up

Question 4

What is a hydrocarbon?

Answer 4

A compound made of atoms of carbon and hydrogen only

Question 5

What is an alkane?

Answer 5

A hydrocarbon with only single bonds

Question 6

Name the first four alkanes

Answer 6

Methane, ethane, propane, butane

Question 7

What is the general formula for alkanes?

Answer 7

CnH2n+2

Question 8

How does boiling point change with the length of an alkane?

Answer 8

The longer the alkane, the higher its boiling point

Question 9

How does viscosity change with the length of an alkane?

Answer 9

The longer the alkane, the more viscous (the thicker) it is

Question 10

How does flammability change with the length of an alkane?

Answer 10

The longer the alkane, the less flammable it is

Question 11

What is fractional distillation?

Answer 11

A process used to separate mixtures of substances with different boiling points

Question 12

What are the steps involved in fractional distillation?

Answer 12

Crude oil is vaporised, different molecules rise up the fractionating column and cool down. Condense at different points on the column.

Question 13

Why is fractional distillation important?

Answer 13

Because the different fractions have different uses

Question 14

What is a fuel?

Answer 14

A substance which when reacted with oxygen releases energy

Question 15

Name five fuels we obtain from crude oil

Answer 15

Petrol, diesel oil, kerosene, fuel oil and liquefied petroleum gases

Question 16

What other uses are there for products of fractional distillation?

Answer 16

Solvents, lubricants, polymers and detergents

Question 17

What is combustion?

Answer 17

The reaction of a fuel with oxygen

Question 18

What are the products of complete combustion?

Answer 18

Carbon dioxide and water

Question 19

When does incomplete combustion occur?

Answer 19

When there is not enough oxygen present

Question 20

What is formed in incomplete combustion

Answer 20

Carbon monoxide

Question 21

Why is carbon monoxide dangerous

Answer 21

It is toxic, taken up by red blood cells in preference to oxygen.

Question 22

What is cracking?

Answer 22

The process of breaking down a long hydrocarbon into smaller hydrocarbons

Question 23

What are the products of cracking?

Answer 23

Short alkanes and alkenes

Question 24

Why is cracking important?

Answer 24

Because smaller hydrocarbons are more useful than longer ones

Question 25

What are alkenes

Answer 25

A hydrocarbon with a double bond

Question 26

What are alkenes used for?

Answer 26

As a starting material to make more useful chemicals

Question 27

What is the general formula for alkenes?

Answer 27

C`n`H`2n`

Question 28

What are the first four alkenes?

Answer 28

Ethene, propene, butene, pentene

Question 29

What do members of a homologous series have in common?

Answer 29

Same general formula, differ by CH2 for neighbouring compounds in the series, boiling points increase with chain length, have similar chemical properties and reactions.

Question 30

How is sulphur dioxide produced?

Answer 30

Sulphur impurities in fuels form it when the fuel is burnt

Question 31

What happens when the sulphur dioxide dissolves in rain water?

Answer 31

Acid rain is formed

Question 32

How are oxides of nitrogen formed?

Answer 32

When the nitrogen and oxygen in the air react together at the high temperatures created in combustion engines

Question 33

State three advantages of hydrogen fuel cells over petrol

Answer 33

Do not need to be recharged, no pollutants are produced only H`2`O, water is a renewable resource

Question 34

State three disadvantages of hydrogen fuel cells over petrol

Answer 34

Hydrogen is highly flammable, hydrogen is sometimes produced through non-renewable means, hydrogen is difficult to store and transport

Question 35

What does finite mean?

Answer 35

It wil run out.

Question 36

How does ease of ignition change with the length of an alkane?

Answer 36

The longer the alkane, the harder it is to ignite.

Question 37

How are members of a homologous series different from each other?

Answer 37

Their chain length differs by a number of CH`2`

Question 38

Where do petrol, kerosene and diesel oil come from?

Answer 38

They are obtained by fractional distillation of crude oil

Question 39

Where does methane come from?

Answer 39

It is found in natural gas?

Question 40

Are petrol, kerosene, diesel and methane renewable or non renewable?

Answer 40

non-renewable