Organic Chemistry

Question 1

Define Organic Chemistry

Answer 1

The study of all compunds originally produced by living organisms, consisting mainly out of hydrocarbons

Question 2

Give the first part of each compounds name according to the number of carbon atoms it contains.
1 -
2 -
3 -
4 -
5 -
6 -
7 - 
8 -
9 -
10 -

Answer 2

1 - meth
2 - eth
3 - prop
4 - but
5 - pent
6 - hex
7 - hept
8 - oct
9 - non
10 - dec

Question 3

Define the term “homologous series”

Answer 3

A family of similar compounds with similar properties due to the same functional group

Question 4

Name the four groups in the homologous series

Answer 4

Alkanes
Alkenes
Alcohols
Carboxylic acids

Question 5

Describe how one would identify an Alkane

Answer 5

Single bond between carbon atoms

Question 6

Describe how one would identify an Alkene

Answer 6

1 or more double bonds between carbon atoms

Question 7

Describe how one would identify an Alcohol

Answer 7

Hydroxide (OH) present in structure

Question 8

Describe how one would identify a Carboxylic Acid

Answer 8

Double bond with oxygen and single bond with hydroxide present in structure

Question 9

State the properties of Alkanes

Answer 9

• Unreactive

- Saturated (Maximum amount of hydrogen atoms bonded to carbon atoms)

Question 10

State the properties of Alkenes

Answer 10

• More reactive

- Unsaturated

Question 11

State the properties of Alcohols

Answer 11

• Functional group OH

Question 12

State the properties of Carboxylic Acids

Answer 12

• Functional group COOH

- Functional group can only be at the end of the molecular chain

Question 13

State the products of a) complete and b) incomplete combustion

Answer 13

a) Carbon Dioxide and Water

b) Carbon Monoxide and Water

Question 14

Define “Cracking” and give an example of the process

Answer 14

The chemical process of breaking down large molecules into smaller, more usefull molecules.
The alkanes in diesel oils can be cracked to obtain more usefull petroleum molecules

Question 15

Give the two products formed when ethane is cracked

Answer 15

Ethene and hydrogen gas

Question 16

Name the product formed when ethene and hydrogen reacts in an addition reaction, and also state the name of the reaction

Answer 16

Ethane

This reaction is reffered to as “hardening”

Question 17

State one use of hardening

Answer 17

Changing unsaturated vegetable oils into margerine

Question 18

State the conditions for hardening

Answer 18

Temperature above 180 degrees and nickel must be used as a catalyst

Question 19

Name the product formed when ethene and water reacts

Answer 19

Ethanol

Question 20

Describe what happens during hardening

Answer 20

The double bond between the carbon atoms in ethene is broken, opening up two more spaces for hydrogen atoms to bond, forming ethane

Question 21

State the conditions under which ethene and water can react to form ethanol

Answer 21

• Temperature of 300 degrees
• Pressure of 70 Pa
• Sulphuric acid as a catalyst

Question 22

Name the product formed when bromine reacts with ethene

Answer 22

Bromoethene

Question 23

Describe how one would distinguish between an alkane and an alkene using bromine

Answer 23

The orange colour of bromine disappears when it reacts with an alkene, due to the fact that an alkene is unsaturated. When an alkane is shaken with bromine, the orange colour remains as all alkanes are saturated

Question 24

Name the catalyst used in polymerisation

Answer 24

Ziegler Catalyst

Question 25

Describe four properties of the industrial manufacturing of ethanol (Reaction of steam and ethene)

Answer 25

The process is continuous Produces pure ethanol Uses crude oil Produced in large volumes cheaply

Question 26

Name the two products required to form glucose during fermentation, and also name the catalyst used

Answer 26

Water and sucrose | Catalyst: Yeast

Question 27

Name the two products formed when liquid glucose is broken up using yeast as a catalyst

Answer 27

Ethanol & carbon dioxide

Question 28

State three conditions for fermentation

Answer 28

- Glucose must be in a solution - Temperature must be below 40 degrees - Yeast must be used as a catalyst

Question 29

Explain why the temperature must be kept below 40 degrees during fermentation

Answer 29

Yeast will denature when exposed to temperatures above 40 degrees

Question 30

Give four properties of the process of fermentation

Answer 30

- Batch process - Produces impure alcohol - Uses renewable resources - Produces small volumes

Question 31

Give two uses of ethanol

Answer 31

- Solvent | - Fuel

Question 32

True or false: | Ethanol supports combustion

Answer 32

True

Question 33

Name the product formed when ethanol (formed during fermentation) comes into contact with atmospheric oxygen

Answer 33

``` Ethanoic Acid (Vinegar) (C2H5OH + O2 = CH3COOH + H2O) ```

Question 34

State why fermentation should be carried out in a closed container

Answer 34

If the container is not closed, the ethanol will come into contact with atmospheric oxygen and will slowly be oxidised into ethanioc acid.

Question 35

State why wine sometimes tastes sour after a prolonged period of exposure to air

Answer 35

Oxygen in the air will slowly react with the ethanol in the wine (this process is known as oxidation), which will result in the formation of ethanoic acid, which is what vinegar is made of. This will give the wine a sour taste

Question 36

State three properties of fossil fuels

Answer 36

- Formed in the remains of ancient buried animals - Oil, petroleum and natural gas are examples - Contain a percentages of hydrocarbons

Question 37

State two properties of natural gases

Answer 37

- Collects above ground in oil deposits | - Methane is the main constituent

Question 38

Define refining

Answer 38

The process of converting into more usefull substances. This process involves fractional distillation and cracking.

Question 39

Define a polymer

Answer 39

Giant, long chained molecule made up of a large number of smaller molecules joined together

Question 40

Define a synthetic polymer

Answer 40

Substances such as plastics, nylon and Terylene

Question 41

Define polymerisation

Answer 41

The chemical process by which monomers join together to form a polymer.

Question 42

Define the process of addition polymerisation

Answer 42

Addition reactions between unsaturated monomers

Question 43

Define polyethene

Answer 43

Polymer formed by up to 50 000 ethene molecules