Organic Chemistry

Question 1

What is the formula of alkanes?

Answer 1

CnH2n+2

Question 2

What are the first 4 alkanes?

Answer 2

Methane
Ethane
Propane
Butane

Question 3

What are the properties of a shorter chain?

Answer 3

Less viscous
More flammable
more volatile

Question 4

What is the equation for combustion?

Answer 4

Hydrocarbon + oxygen —–> carbon dioxide + water

Question 5

What happens to carbon and hydrogen in combustion?

Answer 5

They are oxidised

Question 6

How does fractional distillation work?

Answer 6

Oil is heated and turned to gas
Hottest at the bottom
Long chains at the bottom as they have higher boiling points
Shorter chains at the top as they have a lower boiling point

Question 7

Why are short chains good?

Answer 7

They are flammable so they make good fuels

Question 8

What is cracking?

Answer 8

Thermal decomposition

Question 9

How does cracking work?

Answer 9

Heat to vaporise long chain
Vapor passed over hot powdered aluminium oxide catalyst
Long chain split apart on catalyst surface

Question 10

What is another way of cracking?

Answer 10

Vaporise them
Mix them with steam
Then heat to a very high temperature

Question 11

What is the general formula for alkenes?

Answer 11

CnH2n

Question 12

What are the first four alkenes?

Answer 12

Ethene
Propene
Butene
Pentene

Question 13

What happens if you burn alkenes in the air?

Answer 13

They undergo incomplete combustion

Question 14

What is the word equation for incomplete combustion of alkenes?

Answer 14

Alkene + oxygen —–> carbon + carbon dioxide + water

Question 15

What does incomplete combustion result in?

Answer 15

Smokier flame

Less energy being released

Question 16

What happens in addition reactions of alkenes?

Answer 16

The double carbon bond opens up to leave a single bond and a new atom is added to each carbon

Question 17

What can be added to alkenes?

Answer 17

Halogens
Hydrogen
Steam

Question 18

What is the addition of hydrogen known as?

Answer 18

Hydrogenation

Question 19

What happens in hydrogenation?

Answer 19

Alkene is reacted with hydrogen in the presence of a nickel catalyst

Question 20

What would be the product of ethene + bromine?

Answer 20

Dibromoethane

Question 21

What can be used to test for alkenes?

Answer 21

Bromine water

Question 22

What happens when bromine water is added?

Answer 22

It is first orange then will become colourless when bonds are unsaturated
Forming a dibromo-compound

Question 23

When steam reacts with alkenes what is the product?

Answer 23

Alcohol

Question 24

What happens when steam is reacted with alkenes?

Answer 24

Water is added across the double bond and an alcohol is formed

Question 25

How is steam reacted with alkenes?

Answer 25

In the presence of phosphoric acid (catalyst)

Question 26

What happens after ethanol is formed?

Answer 26

Mixture is passed over a reactor to condense Ethanol and water have a higher boiling point so they condense and unreacted ethene is recycled Alcohol is then purified via fractional distillation

Question 27

What are polymers?

Answer 27

Long chain molecules made up of many repeating smaller molecules called monomers

Question 28

What can unsaturated monomer molecules (alkenes) do?

Answer 28

Open up their double bonds and join together to form polymer chains

Question 29

What is it called when alkenes form polymer chains?

Answer 29

Addition polymerisation

Question 30

How is addition polymerisation done?

Answer 30

Under pressure and a catalyst

Question 31

How do you draw a repeating unit?

Answer 31

``` Replace the double bond with a single bond Add an extra single bond to each carbon Fill the rest up Put a brackets round Put an 'n' outside the brackets ```

Question 32

What is the general formula for alcohols?

Answer 32

CnH2n+1OH

Question 33

What are the four alcohols?

Answer 33

Methanol Ethanol Propanol Butanol

Question 34

What are the properties of alcohols?

Answer 34

Flammable Soluble in water Undergo complete combustion

Question 35

Why are alcohols used as solvents?

Answer 35

They can dissolve things water can't dissolve

Question 36

What can alcohols also be used as?

Answer 36

Fuel

Question 37

What are the conditions needed for fermentation?

Answer 37

Anaerobic 37degrees Enzymes fro yeast Slightly acidic

Question 38

What are carboxylic acids functional group?

Answer 38

COOH

Question 39

What are the four carboxylic acids?

Answer 39

Methanoic acid Ethanoic acid Propanoic acid Butanoic acid

Question 40

What are the properties of carboxylic acids?

Answer 40

Behave as acids Dissolve in water to produce acidic solutions React with carbonates to produce CO2

Question 41

Whats the difference between the structure of alcohols and carboxylic acids?

Answer 41

Carboxylic acids have one more oxygen atom

Question 42

How could alcohols be turned into carboxylic acids?

Answer 42

Adding oxygen (oxidation) + oxidising agent

Question 43

What is the equation for reacting carboxylic acids with carbonates?

Answer 43

Ethanoic acid + sodium carbonate -----> sodium ethanoate + carbon dioxide + water

Question 44

How are esters formed?

Answer 44

From an alcohol and carboxylic acid

Question 45

What are the equation for esters?

Answer 45

Alcohol + carboxylic acid ------>. ester + water

Question 46

What type of catalyst is used to make esters?

Answer 46

Acid catalyst eg. sulfuric acid (concentrated)

Question 47

How is ethyl ethanoate formed?

Answer 47

Ethanoic acid + ethanol ------> Ethyl ethanoate + water

Question 48

What does condensation polymerisation involve?

Answer 48

Monomer of different functional groups

Question 49

What happens when a new bond is formed in condensation polymerisation?

Answer 49

A small molecule (water) is lost

Question 50

Number of types of monomer?

Answer 50

A- one | C- two or one with two functional groups

Question 51

Number of products?

Answer 51

A- one | C- two (polymer + small molecule)

Question 52

Functional group involved?

Answer 52

A- carbon double bond | C- two reactive groups on each monomer