Topic 7 - Organic Chemistry

Question 1

What is a hydrocarbon?

Answer 1

A molecule that is formed only from hydrogen and carbon

Question 2

What are the first four alkanes?

Answer 2

Methane
Ethane
Propane
Butane

Question 3

What is the formula for alkanes?

Answer 3

CnH2n+2

Question 4

What are saturated compounds?

Answer 4

Each carbon atom has four single bonds, no double bonds

Question 5

What are the properties of alkanes as chin size increases?

Answer 5

Boiling point increases
Volatility decreases due to high boiling point
Flammability decreases
Viscosity increases

Question 6

What is the formula for complete combustion?

Answer 6

Hydrocarbon + oxygen -> Co2 + water

Question 7

What is fractional distillation?

Answer 7

The process of separating crude oil into its hydrocarbon components

Question 8

How is crude oil made?

Answer 8

Plankton that died millions of years ago and got buried.
They got turned into crude oil by high temperatures and pressures
They can be drilled out of the rock

Question 9

What are the key features of fractional distillation?

Answer 9

A fractional column that is cooler toward the top.
Hydrocarbons will condense into a liquid a certain points when the become cooler than there boiling points

Question 10

What is cracking?

Answer 10

Cracking is a thermal decomposition reaction which uses heat to break down hydrocarbons

Question 11

What are the two types of cracking?

Answer 11

Steam cracking
Catalytic cracking

Question 12

What are the steps to catalytic cracking?

Answer 12

Vaporise the alkanes
Pass over aluminium oxide powder
This causes them to split apart

Question 13

What are the steps of steam cracking?

Answer 13

Vaporised alkanes
Mix with steam
Heat to high temp so alkanes are split

Question 14

What is an alkene?

Answer 14

An hydrocarbon with a double bonded carbon

Question 15

What is the formula for alkenes?

Answer 15

CnH2n

Question 16

What forms during cracking?

Answer 16

An alkane and an alkene

Question 17

Are alkenes saturated or unsaturated and why?

Answer 17

Unsaturated because they contain two fewer hydrogen atoms than the alkane with the same number of carbon atoms.

Question 18

What are the difference between alkanes and alkenes?

Answer 18

Alkenes are more reactive so when added to bromine water it will turn from orange to colourless
Alkenes can be added together to form polymers by breaking their double bond

Question 19

What is the test for alkenes?

Answer 19

Adding them to bromine water should turn it colourless

Question 20

What are the three types of addition reactions with alkenes?

Answer 20

Hydrogen
Water
Halogen

Question 21

Explain the addition reaction with alkenes and hydrogen

Answer 21

Hydrogen and alkene passed over catalyst to from alkane

Question 22

Explain the addition creation with alkene and water

Answer 22

Ethene and water over catalyst with high temperatures from ethanol

Question 23

How can you separate water and ethanol

Answer 23

With fractional distillation

Question 24

Explain the addition reaction with an alkene and a halogen

Answer 24

Ethene and bromine into colourless dibromoethane - an alkane. This is how the test for alkenes takes place.

Question 25

Do alkenes react with oxygen and how?

Answer 25

Yes, the react with oxygen in combustion reactions but they produce smoky flames due to incomplete combustion.

Question 26

How can alkenes make polymers?

Answer 26

By addition polymerisation

Question 27

What is addition polymerisation?

Answer 27

The process in which many small monomers join together right form very large polymers

Question 28

What functional group does an alcohol contain?

Answer 28

An OH

Question 29

What is the general formula for an alcohol group?

Answer 29

CnH2n+1OH

Question 30

What happens when an alcohol reacts in air?

Answer 30

Combustion reaction where alcohol and oxygen form carbon dioxide and water

Question 31

What happens when an alcohol is added to water?

Answer 31

The alcohol will dissolve into water with and have a neutral pH

Question 32

What happens when an alcohol reacts with an oxidising agent?

Answer 32

It forms a carboxylic acid

Question 33

What happens when an alcohol reacts with sodium?

Answer 33

It forms hydrogen and a salt e.g sodium ethoxide

Question 34

What is condensation polymerisation?

Answer 34

Involves the use of two functional groups and usually loses a small molecule like water

Question 35

What is needed for condensation polymers?

Answer 35

Each monomer has to have at least two functional groups. And there overall needs to be two different functional groups.

Question 36

How can ethanol be created by fermentation and what are the necessary conditions?

Answer 36

Fermentation of sugar using yeast cells. Around 30-40 degrees for optimum temperature of enzymes and anaerobic conditions so the thankless isn’t oxidised.

Question 37

How can ethanol be produced using steam?

Answer 37

Needs a temp of 300c and 60-70 atmospheres pressure over a catalyst. Reacts ethene with steam

Question 38

What is the functional group for a carboxylic acid and what is the end of the name of a chemical in the series?

Answer 38

COOH and ends in ..anoic acid

Question 39

What are carboxylic acids weak?

Answer 39

Because they don’t fully ionise.

Question 40

What happens when a carboxylic acid reacts with a metal carbonate and give an example?

Answer 40

Carboxylic acid + metal carbonate -> salt. + water + carbon dioxide Ethanoic acid +. Potassium carbonate -> potassium ethanoate + water + carbon dioxide

Question 41

How are carboxylic acids made?

Answer 41

By reacting an alcohol with an oxidising agent to add thee required oxygen for the functional group

Question 42

What is the functional group of an ester?

Answer 42

COO

Question 43

What are the properties of esters?

Answer 43

Easily evaporate, volatile and have pleasant smells

Question 44

How are esters made and what happens during the reaction?

Answer 44

Reacting a carboxylic acid and an alcohol. The acid loses a PH group. And the alcohol loses a Hydrogen to form a water molecule.

Question 45

What are three naturally occurring polymers?

Answer 45

Polypeptides, DNA, Carbohydrates

Question 46

What makes a polypeptide a polymer - how is it made?

Answer 46

The reaction of amino acids by condensation polymerisation. This is because an amino acid contains a carboxylic acid group and a amino group.

Question 47

What are the monomers of DNA?

Answer 47

Nucleotides

Question 48

How are carbohydrates a polymer - how are they made?

Answer 48

They are made of monomers which are made of carbon, oxygen and hydrogen. The monomers join together to form polysaccharides.