C7 Biological Chemistry

Question 1

What is the simplest organic compound?

Answer 1

A hydrocarbon

Question 2

What is a hydrocarbon?

Answer 2

Any compound formed from carbon and hydrogen atoms only

Question 3

What is an alkane

Answer 3

• The simplest type of hydrocarbon
• Saturated compounds (each carbon atom forms 4 single bonds)

Question 4

What are the first four alkanes?

Answer 4

Methane, ethane, propane, butane

Question 5

What happens to the hydrocarbon properties as the chain length gets longer?

Answer 5

• Higher viscosity
• Higher BP and MP
• Lower flammability

Question 6

What is the complete combustion reaction for hydrocarbons?

Answer 6

Hydrocarbon + Oxygen
-> Carbon dioxide + Water

Question 7

What is one use for a hydrocarbon?

Answer 7

Used as a fuel

Question 8

What is crude oil?

Answer 8

A fossil fuel formed from ancient biomass that has been under pressure and high temperature for millions of years

Question 9

What does non renewable mean?

Answer 9

It is a finite resource

Question 10

How does fractional distillation work?

Answer 10

• The oil is heated until most of it has turned in to a gas
• In the column there is a temperature gradient
• The longer hydrocarbons have high boiling points, meaning they condense and drain out of the column early on; The short hydrocarbons have lower BP so they condense and drain out at a later time

Question 11

What is cracking? What are the conditions needed in this process?

Answer 11

The breaking of longer chain hydrocarbons in to shorter ones. High temperature and a Catalyst

Question 12

As well as alkanes, what else does cracking produce?

Answer 12

Alkenes

Question 13

What are the two different types of cracking?

Answer 13

Thermal cracking and catalytic cracking

Question 14

What are Alkenes

Answer 14

Hydrocarbons which have a double bond between two of the carbon atoms in their chain

Question 15

What are the first four alkenes?

Answer 15

Ethene, Propene, Butene, and pentene

Question 16

Why is there no Alkene with one carbon atom?

Answer 16

Because alkenes need a double carbon bond to be classified as an ethene

Question 17

What is the standard reaction for the incomplete combustion of ethenes in air?

Answer 17

Alkene+ Oxygen -> Carbon + Carbon monoxide + Carbon dioxide + Water

Question 18

How can the addition of bromine to a double bond be used to test for alkenes?

Answer 18

• When orange bromine water is added to a saturated compound, like an alkane, no reaction will happen and it will stay bright orange
• If its added to an alkene the bromine will add across the double bond, making a colourless dibromo- compound- so the bromine water is decolourised

Question 19

What are plastics made out of?

Answer 19

Made up of polymers

Question 20

What is polymerisation?

Answer 20

The joining of small monomers to form a polymer

Question 21

What type of bond do monomers have that make up the addition polymers?

Answer 21

A double carbon bond

Question 22

What is an alcohol?

Answer 22

A homologous series of organic compounds

Question 23

What are the first four alcohols in the homologous series?

Answer 23

Methanol
Ethanol
Propanol
Butanol

Question 24

What are alcohols uses

Answer 24

• Fuel
• Solvents
• Drinks

Question 25

What is the process of fermentation?

Answer 25

Using sugar and the enzyme yeast, you can make ethanol + Carbon dioxide

Question 26

What are carboxylic acids?

Answer 26

A homologous group of compounds that all have -COOH as a functional group

Question 27

What are the first four carboxylic acids?

Answer 27

Methanoic acid Ethanoic acid Propanoic acid Butanoic acid

Question 28

How do carboxylic acids react with carbonates?

Answer 28

Ethanoic acid + Sodium Carbonate -> Sodium ethanoate + water + carbon dioxide

Question 29

What functional group do esters have?

Answer 29

They have the functional group of COO

Question 30

How are esters made?

Answer 30

Formed from Alcohol and a carboxylic acid

Question 31

What is the formula for making a ester?

Answer 31

Alcohol + Carboxylic acid -> Ester + Water

Question 32

What is condensation polymerisation?

Answer 32

- involves monomers which contain different functional groups - Monomers react together and bonds form between them, making polymer chains - For each new bond between them, a small molecule ( Water) is lost

Question 33

What are examples of naturally occurring polymers?

Answer 33

- DNA - Proteins - Starch - Cellulose

Question 34

What are the monomers that protein is made up of?

Answer 34

Proteins are made up of chains of amino acids

Question 35

What are the two different functional groups in amino acids?

Answer 35

- A basic amino group - An acidic carboxyl group

Question 36

What are the monomers that DNA is made up from?

Answer 36

Nucleotides

Question 37

Why is bitumen not used as a fuel?

Answer 37

Because the hydrocarbon chain is long, the properties are: - High viscosity - High boiling point - Low flammability

Question 38

Why are longer hydrocarbon chains cracked to make shorter hydrocarbon chains?

Answer 38

- They have a greater demand - They are more useful - Better fuels - Used to make polymers and alkenes

Question 39

What kind of reactions are ethane and ethene involved in?

Answer 39

- Both react with oxygen in complete combustion reactions to produce water and carbon dioxide - ethene decolourises bromine water but ethane doesnt - Ethene is more reactive than ethane - Ethene can react with hydrogen, water, halogens, and can undergo addition reactions - Ethene can also polymerise to produce polyethene

Question 40

Why does carbon dioxide make lime water turn cloudy?

Answer 40

They react which forms a white precipitate of solid calcium carbonate causing it to be clouded

Question 41

What kind of catalyst is needed to enable a reaction between carboxylic acids and alcohols? What does it form?

Answer 41

You need an acid catalyst and it will form a pleasant smelling compound like an ester

Question 42

How can you tell from an ionisation reaction if an acid is weak?

Answer 42

If its reversible it is a weak acid because there would only be a partial ionisation ( Some of reactants not ionised)

Question 43

What happens when you react Ethanol and Ethanoic acid?

Answer 43

Ethyl Ethanoate + Water