3.1 - Additional Organic

Question 1

Functional group examples

Answer 1

1. Alkanes - C - C
2. Alkenes - C = C
3. Alcohols - O - H -anol
4. Carboxylic acids - COOG - anoic acid

Question 2

What is the difference between molecular and structural formula?

Answer 2

A molecular formula is a formula that shows the number and types of atom present
-this is a formula that shows the number and type of atoms present and how they are arranged

Question 3

What are isomers?

Answer 3

These have the same molecular formula but different structural formula

Question 4

Explain how ethanol is made by fermentation

Answer 4

Starting materials: glucose, water yeast
Glucose = ethanol + carbon dioxide
Anaerobic respiration - done in the absence of oxygen
-20% alcohol because the ethanol kills the yeast above this amount
-temp of 25-35 celcius
-it releases Co2 but is absorbed to make the sugar so it is carbon neutral
-yeast is removed by filtering and ethanol & water is distilled to get water

Question 5

What is the formula for alkanes and alkenes?

Answer 5

Alkanes = Cn H2n+2
Alkenes = CnH2n

Question 6

What is the symbol equation for

Glucose= ethanol + carbon dioxide

Answer 6

C6H12O6 = 2C2H5OH+2CO2

Question 7

What is the test to identify ethanoic acid?

Answer 7

Use sodium carbonate and see if it fizzes

Question 8

What colour is ethanoic and sulphuric acid in universal indicator?

Answer 8

Ethanoic acid = turns orange

Sulphuric acid= turns red

Question 9

What are the observations with magnesium for ethanoic and sulphuric acid?

Answer 9

• ethanoic acid= fizzes slowly, heat can be lost

- sulphuric acid= fizzes vigorously, heat produced quickly

Question 10

Describe why sulphuric acid is a strong acid

Answer 10

It fully dissociates (ionises) into its ions
H2S04 = 2H+ + SO2-
4

Question 11

Describe why ethanoic acid is a weak acid

Answer 11

It does not fully dissociate into its ions, it only partially dissociates
CH3= H+ + CH3COO-

Question 12

What are the social advantages and disadvantages of the use of the alcoholic drinks?

Answer 12

Ad:
-makes people relaxed

Dis:

• liver damage
• antisocial behaviour
• domestic violence
• family breakdown due to alcoholism

Question 13

Economic advantages and disadvantages of alcoholic drinks

Answer 13

Ad:

• revenue for government through taxes
• jobs in brewing industry

Dis:

• increased police costs for antisocial behaviour
• increased costs for NHS due to alcohol related illnesses

Question 14

Why does air have to be absent for the process of fermentation?

Answer 14

Because if air was present then ethanoic acid would be made

Question 15

What is the method used to obtain ethanol from the mixture?

Answer 15

Fractional distillation

Question 16

How to recover yeast?

Answer 16

By filtration

Question 17

What is a homologous?

Answer 17

A family of compounds with the same functional group. The second part of the name tells us the homolygous series it is in

Question 18

What are the necessary conditions for fermentation to occur?

Answer 18

A glucose solution

• temperature from 25 to 35 degrees
• absence of oxygen
• a pH in the range 4-7

Question 19

Why is ethanol the first liquid to be collected in the beaker?

Answer 19

It has a lower boiling point

Question 20

What are the advantages of ethanol as a fuel?

Answer 20

• carbon neutral
• renewable resource
• does not produce sulfur dioxide
• reduces the demand on fossil fuels

Question 21

What are the disadvantages of ethanol as a fuel?

Answer 21

• needs a lot of land to grow crops
• needs a lot of sunlight to grow crops
• food shortages as land used for fuel and not food

Question 22

What can ethanol be used as a solvent for?

Answer 22

• disinfectant

- manufacture for varnishes and perfumes

Question 23

Control measures to keep safe with ethanol in an experiment

Answer 23

• highly flammable so keep lid on at all times unless it is being used
• beaker will become hot so clamp it

Question 24

How to reduce heat (fire triangle)

Answer 24

Add water

Question 25

How to remove oxygen (air) in a fire triangle?

Answer 25

• foam to extinguish the aircraft fire
• fire blanket for a chip pan fire or a person
• carbon dioxide powder to put out indoor fires, chemical and electrical fires

Question 26

How to remove fuel? (FT)

Answer 26

Switch off electrical or gas supply

-fire breaks for forest fires

Question 27

What is the process called that ethanol undergoes to be ethanoic acid?

Answer 27

Microbial oxidation