Alcohols 3.3.5

Question 1

When you have a compound that has an alcohol and a higher priority group, how do you name it

Answer 1

Hydroxy as the beggining prefix

Question 2

There are primary, secondary and tertiary Alcohols, which ones are the most stable

Answer 2

Tertiary alcohol ad alkyl groups donate electrons to carbon atom which increases stability

Question 3

Why do Alcohols have a greater boiling point than alkanes with a similar Mr

Answer 3

Alkenes only had VDW forces betweeb molecules
Alcohols have VDW forces and hydorgen bonding between molecules
Hydrogen binding is a stronger intermolecular force than VDW force therefore requires more energy to overcome

Question 4

Why are Alcohols soluble in water

Answer 4

OH group can form Hydrogen bonds with water molecules

Question 5

Explain the link between size of Alcohols and solubility and give the reasoning

Answer 5

As chain length of alcohol increases, solubility decreases as non polar VDW dominate

Question 6

What are the uses of alcohol

Answer 6

Fuels
Solvents
Alcoholic drinks

Question 7

What are the 2 ways of producing ethanol

Answer 7

Hydration of ethene
Fermentation

Question 8

What are the conditions needed in the Hydration of ethene

Answer 8

Concentrated phosphoric acid
300°C
60 atmospheres
Excess steam

Question 9

Ethanol SAMSUNG NOTES

Answer 9

🍨

Question 10

Give a brief summary of hoe ethanol is produced from fermentation

Answer 10

Carbohydrates in plants broken down to sugars
Then converted into ethanol by the action of enzymes from yeast

Question 11

Give the symbol ewuation for ethanol production via fermentation
What are the conditions

Answer 11

C6H12O6 -> 2C2H5OH + 2CO2
Anaerobic
Yeast
37°

Question 12

Why are anaerobic conditions used during fermentation

Answer 12

Oxygen from air is kept put to prevent oxidation of ethanol to ethanoic acid

Question 13

Industrial fermentation is carried out at 37°C rather than 25°C, what is an advantage and disadvantage

Answer 13

ADVANTAGE Ethanol is produced at a faster rate
DISADVANTAGE more energy used

Question 14

What is the issue with ethanol produced during fermentation and how is this dealt with

Answer 14

Ethanol is Impure as it is aqeuoues
Use Fractional distillation to sperate water and ethanol as they have different boiling points

Question 15

Fermentation Samsung notes

Answer 15

🍓

Question 16

What is the mechanism when Alcohols are turned into alkenes

Answer 16

Elimination (dehydration)

Question 17

Elimination Samsung notes

Answer 17

🎊

Question 18

What needs to be present for an alcohol to be oxidised and what is the specific one used here

Answer 18

Oxidising agent (acidification potassium dichromate)

Question 19

Alcohols can be oxidised by oxidising agents into….

Answer 19

Carboxylic acids, aldehyde, ketone

Question 20

When acidified potassium dichromate is reduced, explain the colour change when alcohol is oxidised

Answer 20

Orange to green

Question 21

What can primary Alcohols be oxidised into

Answer 21

Aldehyde and carboxylic acid

Question 22

What can secondary Alcohols be oxidised into

Answer 22

Ketone

Question 23

When primary Alcohols are oxidised into Aldehyde, what are the required conditions

Answer 23

Acidified, heat, distillation

Question 24

When primary Alcohols are oxidised to carboxylic acids, what are the required conditions

Answer 24

Acidified, heat under reflux and excess acidified potassium dichromate (VI) solution

Question 25

When secondary Alcohols are oxidised into ketones, what are the required conditions

Answer 25

Acidified, heat under reflux

Question 27

When an alcohol is being oxidised, what symbol do we use above the arrow What about if it is in excess for example when primary Alcohols are oxidised into carboxylic acids

Answer 27

[O] 2[O]

Question 28

What is refluxing and when is this used

Answer 28

The continuous boiling and condensing if a reaction mixture This is used when you have volatile reactants

Question 30

In distillation, why does water enter from the bottom of the condenser What would happen if water entered from the top

Answer 30

To allow efficient cooling If water entered from the top, the hot vapour would heat up the vapour so water would not be cool enough to allow efficient condensation

Question 31

Why do tertiary Alcohols not get oxidised

Answer 31

They don't react with potassium dichromate so it does not get oxidised by it

Question 32

In terms of elements, in oxidation of Alcohols, what does the oxidising agent remove

Answer 32

It removes H from OH group and H from C attached to OH group

Question 33

Why are antibumping granules added in distillation and reflux

Answer 33

To make boiling smoother by forming small, even bubbles

Question 34

TOLLEN'S REAGENTS(SILVER MIRRPR TEST) What ions does it contain? What is it reduced to? What colour is this? What is this used to test for

Answer 34

Other contains colourless Ag+ ions which are reduced to Ag Metallic silver colour (colourless solution forms a silver mirror) Used to test for aldehydes that are being oxidised we ketones cannot be oxidised so no reaction

Question 36

Whar are the two tests for differentiating between a ketone and aldehyde

Answer 36

Tollens' reagents Fehling's solution

Question 37

Explain the fehling's solution test

Answer 37

Contains Copper(II) ions It is a blue solution and when warmed in the presence of an aldehyde, a brick red precipitate of copper(I) oxide forms

Question 38

How to test for carbon dioxide

Answer 38

Bubble the gas through liimwater and limewater turns cloudy if carbon dioxide is present

Question 39

Last week SAMSUNG NOTES

Answer 39

🍭