T3 - Alkanes and Crude Oil

Question 1

What is a Hydrocarbon

Answer 1

A compound made up of hydrogen and carbon only

Question 2

what does the empirical formula show

Answer 2

the simplest possible ratio

Question 3

what does molecular formula show

Answer 3

the actual number of atoms in a molecule

Question 4

what does the general formula show

Answer 4

a ratio of atoms in a family of compounds in terms of ‘n’

Question 5

what is the general formula for alkanes

Answer 5

CnH2n+2

Question 6

What does a displayed formula show?

Answer 6

the spatial arrangement of all the atoms and bonds in a molecule

Question 7

What does a structural formula show?

Answer 7

arrangement of atoms

Question 8

what is a homologous series

Answer 8

a series or family of organic compounds that have similar features and chemical properties due to them having the same functional group

Question 9

what do all members of a homologous series have

Answer 9

• same general formula
• same functional group
• similar chemical properties
• gradation in their physical properties

Question 10

what is a functional group

Answer 10

a specific atom or group of atoms that give out certain physical and chemical properties onto the molecule

Question 11

What is isomerism?

Answer 11

Compounds that have the same molecular formula but different structural formula

Question 12

why are alkanes classified as saturated hydrocarbons

Answer 12

they have a carbon to carbon single bond only

Question 13

what is fuel

Answer 13

a substance that releases heat energy when burned

Question 14

what is complete combustion

Answer 14

burning in a plentiful supply of oxygen

Question 15

What is incomplete combustion?

Answer 15

burning in a limited supply of oxygen

Question 16

what are the products of complete combustion

Answer 16

carbon dioxide and water

Question 17

what are the products of incomplete combustion

Answer 17

Carbon monoxide and water and carbon (in the form of soot) and carbon dioxide

Question 18

Why is carbon monoxide poisonous?

Answer 18

Reduces the ability of the blood to carry oxygen around the body

Question 19

Reduces the ability of the blood to carry oxygen around the body

Answer 19

combustion of fuels in car engines causes high temperatures to be reached, allowing nitrogen and oxygen from the air to combine to produce nitrogen monoxide

Question 20

what happens when nitrogen monoxide is released from the exhaust of car engines

Answer 20

nitrogen monoxide combines with oxygen in the air to form nitrogen dioxide

Question 21

how does the combustion of some impurities in hydrocarbon fuels result in the formation of sulfur dioxide

Answer 21

when hydrocarbon fuels combust, impurities including sulfur compounds are oxidised which produces sulfur dioxide

Question 22

What is acid rain?

Answer 22

rain with low pH due to presence of dissolved acidic gases such as sulfur dioxide and oxides of nitrogen

Question 23

how do sulfur dioxide and oxides of nitrogen contribute to acid rain

Answer 23

sulfur dioxide reacts with oxygen and dissolve in water droplets of clouds forming Sulfuric acid - causing acid rain

oxides of nitrogen react with oxygen and dissolve in water droplets of clouds forming nitrous acid - causing acid rain

Question 24

Simple Distillation - Method

Answer 24

it is used to separate a liquid from a solution.
method:
- solution is heated and water vapours will rise and evaporate
- the water vapours pass through a condenser where they cool and condense - the condenser turns them into a liquid that is collected in a beaker
- when all the water vapour has evaporated from the solution, the solute will be left behind

Question 25

fractional distillation

Answer 25

Method to separate a liquid mixture into its individual components

Question 26

simple distillation

Answer 26

Used to obtain a solvent from a solution

Question 27

fractional distillation - method

Answer 27

-the mixture is heated to the temperature of the substance with the lowest boiling point
- vapours of this substance will then evaporate
- they will pass through a condenser where it cools and condenses - turning the vapours into a liquid - they are then collected in a beaker
- after all of the substance with the lowest boiling point has evaporated and been collected - the mixture will be separated into its individual components

Question 28

what is crude oil

Answer 28

a mixture of hydrocarbons

Question 29

industrial fractional distillation method

Answer 29

• in a fractioning column, it is hot at the bottom and cool at the top
• crude oil is transported into the fractioning column and heated into vapours that will rise and evaporate
• vapours of hydrocarbons with high boiling points will turn into liquids at the bottom of the fractioning column
• vapours of hydrocarbons with low boiling points will condense at the top of the fractioning column

Question 30

uses of refinery gases

Answer 30

domestic heating and cooking

Question 31

Uses of gasoline

Answer 31

fuel for cars

Question 32

uses of kerosene

Answer 32

fuel for jets

Question 33

uses of diesel

Answer 33

fuel for cars and lorries

Question 34

Uses of fuel oil

Answer 34

Fuel for ships and power stations

Question 35

uses of bitumen

Answer 35

road surfacing

Question 36

what happens to the change in colour as you move down the fractioning column

Answer 36

it gets darker

Question 37

what happens to the change in boiling point as you move down the fractioning column

Answer 37

the boiling point increases

Question 38

what happens to the change in viscosity as you move down the fractioning column

Answer 38

the viscosity increases

Question 39

What is viscosity?

Answer 39

the resistance of a liquid to flow