Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

A-Level Chemistry > Alcohols > Flashcards

Alcohols Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

What is the general formula for alcohols?

A

CnH2n+1OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Describe the process of fermentation

A

Extract sugar
Add yeast
Ferment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the conditions needed for fermentation?

A

30-40degrees
CO2 released
Batch process (start + stop)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the equation for fermentation?

A

Glucose —-> ethanol + carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the symbol equation for fermentation?

A

C6H12O6 (aq) —-> 2CH3CH2OH (aq) + 2CO2 (g)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the advantages of fermentation?

A

Sugar = renewable resource
Batch process = cheap
More carbon neutral

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the disadvantages of fermentation?

A

Very slow
Impure = needs fractional distillation = takes time + money
High labour costs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the process of hydration of ethene

A

Extract crude oil
Fractional distillation then cracking
Hydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the conditions needed for the hydration of ethene?

A

Phosphoric acid catalyst
High temperatures + pressure
Continuous process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the equation for hydration of ethene?

A

Ethene + water —-> ethanol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the symbol equation for hydration of ethene?

A

C2H4 + H2O —-> CH3CH2OH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the advantages of hydration of ethene?

A

Fast
Pure
95% yield
Continuous = cheaper manpower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the disadvantages of hydration of ethene?

A

High tech equipment = expensive initially
High energy costs
Non-renewable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the differences between alcohols and alkanes that have the same no. of carbon atoms?

A

Less volatile
Higher melting point due to H bonding
Greater water solubility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Are methanol and ethanol soluble in water?

A

YES

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why is ethanol and methanol soluble in water?

A

H bonds form between the OH group of the alcohol and water molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What happens to solubility as chain length increases?

A

Solubility decreases since influence of OH group decreases

18
Q

What does classifying alcohols depend on?

A

No. of H atoms and alkyl groups attached to the carbon atom that contains the alcohol functional group

19
Q

What must a primary alcohol have?

A

At least 2 H atoms

1 carbon centre

20
Q

What must a secondary alcohol have?

A

1 H atom

2 carbon centres

21
Q

What must a tertiary alcohol have?

A

No H atoms

3 carbon centres

22
Q

What happens to the significance of H bonding as chain length increases and what does this mean?

A

H- bonding significance decreases and London forces increase

This means gap between B.Pts of alcohols and alkanes narrow

23
Q

What does an oxidising agent help something to do?

A

Gain oxygen or lose electrons

24
Q

What happens to primary alcohols when they are oxidised?

A

They oxidise to form an aldehyde and water

25
Q

What does the oxidising agent always take off the alcohol?

A

Takes a H off the alcohol group and a H off the carbon to produce water

26
Q

What is the oxidising agent used in the oxidation of alcohols?

A

Sodium or potassium dichromate (VI)

27
Q

What is the formula for sodium and potassium dichromate (VI)?

A

Na2Cr2O7

K2Cr2O7

28
Q

What must the oxidising agent be in the oxidation of alcohols?

A

Acidified

29
Q

What does an oxidising agent do?

A

Helps things to be oxidised so themselves can be reduced

30
Q

What colour does the oxidising agent change from?

A

Orange to green

31
Q

What happens in the oxidation of an aldehyde?

A

They oxidise to form a carboxylic acid

The oxygen goes on the H

32
Q

What is further oxidation?

A

When an alcohol is oxidised twice to form a carboxylic acid

33
Q

What is mild oxidation?

A

When an alcohol is oxidised once to form an aldehyde

34
Q

What is reflux?

A

Continuous evaporation + condensation (reactants can’t escape the flask)

35
Q

What happens in the oxidation of secondary alcohols?

A

They oxidise to form ketones

36
Q

What can’t happen to ketones?

A

They can’t be oxidised further

37
Q

What happens in the oxidation of secondary alcohols to ensure the reaction is complete?

A

Alcohol is heated under reflux with oxidising mixture

38
Q

What happens to the dichromate (VI) ions in the oxidation of secondary alcohols?

A

Changes from orange to green

39
Q

What happens in the oxidation of tertiary alcohols?

A

Nothing they can’t undergo oxidation reactions

40
Q

What happens to the dichromate (VI) ions in the oxidation of tertiary alcohols?

A

They remain orange

A-Level Chemistry (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions