Brainscape's Knowledge GenomeTM

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


See full index

A Level Chemistry > 14. Alcohols > Flashcards

14. Alcohols Flashcards

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

Where is the OH in aromatic alcohols?

A

attached directly to the ring

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

Why do alcohols have higher boiling points than alkanes?

A

alcohols have permanent d-d interactions and H bonds, which are the strongest kind of IMF, requires more energy to break than just LDFs in alkanes

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

Why would 2-methylpropan-2-ol have a lower bp than butan-1-ol?

A

2-mp2 is more branched, reduces contact points & LDFs, less energy required to overcome IMFs and boil

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

Why would butan-2-ol have a lower bp than butan-1-ol?

A

butan-1-ol is slightly longer and butan-2-ol cannot pack as closely due to branches of OH group, meaning LDFs slightly weaker

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

Are alcohols miscible with water and what is the trend with increasing Mr ?

A

low Mr yes bc H bonding
higher Mr less miscible bc chain is too long to fit between H2O molecules bc it is non-polar and not attracted to H2O molecules

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

Are alcohols a good solvent?

A

yes for both organic and aqueous (universal-esque solvent)

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

2 chemical properties of alcohols

A 
are bases (proton acceptors)
are nucleophiles (electron pair donors)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why are longer chain alcohols worse fuels than shorter chain?

A

vaporise less easily: there are too many IMFs to break: inefficient to overcome all LDFs

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

What catalyst is used in oxidation of alcohols? What is the colour change?

A

acidified potasium dichromate (K2Cr2O7)
changes orange to green
actual reagent is acidified dichromate ion (H+/Cr2O7^2-) (acidified by H2SO4)

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

What do you get if you heat gently and distil the product of the oxidation of a primary alcohol?

A

aldehyde

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

Why can you distil off an aldehyde?

A

it has no H bonding so it can be distilled at the lowest boiling point before being further oxidised FINISH THIS

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

What are the conditions for creating carboxylic acids?

A

primary alcohol, heat strongly under reflux, acidified potassium dichromate
or aldehyde, keep heating, reflux, acidified potassium dichromate

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

What is potassium dichromate in the oxidation of alcohols?

A

oxidising agent

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

How do you make ketones when oxidising alcohols?

A

secondary alcohol, reflux, acidified potassium dichromate

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

Why can you not oxidise a tertiary alcohol?

A

the alcohol group is attached to a carbon that’s attached to 3 other carbons, therefore it cannot lose a hydrogen from the central carbon to become an aldehyde, carboxylic acid or ketone

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

Why do we use reflux?

A

prevents the loss of volatile substances and increases yield

17
Q

In which oxidations of alcohol is water created?

A

alcohol => aldehyde
alcohol => carboxylic acid
alcohol => ketone

18
Q

What are the important parts to include when drawing distillation apparatus?

A

inner tube, heat source, pear shaped flask, in (base) and out (top) flows of water

19
Q

Why do you heat strongly when making a carboxylic acid?

A

if aldehyde is created, it condenses back into the mixture and gets oxidised again to carboxylic acid

20
Q

What are the conditions for the dehydration of alcohols => alkenes + water?

A

reflux, conc. H3PO4 catalyst

21
Q

What are the reagents and conditions for the esterification of alcohols?

A

alcohol + carboxylic acid (or acyl chloride)

small vol. conc. H2SO4 catalyst (homogeneous), reflux/heat

22
Q

what are the uses of esters?

A

flavourings, solvents, plasticisers

23
Q

Where does the OH of the water produced in esterification come from?

A

the carboxylic acid

24
Q

What is the product of a substitution reaction of alcohol?

A

haloalkane + water

25
Q

What are the reagents and conditions for the substitution reactions of alcohols?

A

hydrogen halide, NaBr and H2SO4

H2SO4, reflux, sodium halide

26
Q

How is the hydrogen halide made in substitution reactions of alcohols?

A

in-situ by refluxing the alcohol with NaBr and H2SO4

27
Q

KATY REMEMBER DONT DO MOLECULAR FORMULA DO STRUCTURAL

A

don’t fuck it up x

28
Q

In what 3 ways can you prepare alcohols?

A

haloalkanes (nucleophilic substitution)
aldehydes (reduction)
alkenes (direct hydration: steam + phosphoric acid)

29
Q

What are some uses of alcohols?

A

alcoholic drinks, solvent (meths), fuel, chemical feedstock

30
Q

What is the bond angle around the func. group carbon of an aldehyde?

A

120 degrees

A Level Chemistry (30 decks)

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