Brainscape's Knowledge GenomeTM

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


See full index

A2 Chemistry (PL) > PL2 - The Nylon Story > Flashcards

PL2 - The Nylon Story 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 are amines?

A

Homologous series resembling ammonia.

1, 2, or 3 of the hydrogen groups are replaced by alkyl groups however

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

What are primary amines?

A

Amines with one alkyl group

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

How are primary amines named?

A

Where there might be confusion about where the -NH2 group is attached to a chain, they are named using the “amino” form.

E.g. 2-amino propane

Unless methyl or ethyl amine

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

Which type of amine is used to make condensation polymers?

A

Diamines

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

What are secondary amines?

A

Amines with two alkyl groups

(2 Hs of ammonia have been replaced)

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

What are tertiary amines?

A

Amines where all three hydrogens of ammonia are replaced with alkyl groups

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

What are quaternary amines?

A

They don’t exist!

This is an ammonium ion, NH4+

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

How are secondary amines named?

A

By adding the name of the alkyl chain to ‘amine’ (usually with di-)

E.g. dimethylamine

In more complex ones, both alkyl chains named alphabetically

E.g. Ethylpropylamine

(Not likely to be given more complex ones in exam)

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

How are tertiary amines named?

A

Similarly to secondary amines - add prefix of alkyl group and usually tri-

E.g. Trimethylamine

More complex ones might be: Diethylmethylamine

(Not likely to come across more complex ones in exam)

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

What are diamines?

A

Amines with two amino group attached

(AKA alkyl chains with two amino groups)

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

How are diamines named?

A

Named after the partent alkane with the prefix diamino- (and numbered)

E.g. 1,6-diaminohexane

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

How are branched diamines named?

A

The same as normal diamines but the branched alkyl group prefix is added after

E.g. 1,5-diamino-2-methylpentane

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

What state are amines with a low relative molecular mass in at standard conditions?

A

Gases/volatile liquids.

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

How do volatile amines resemble ammonia?

A

Not only are they volatile but they also have strong smells like rotting fish or flesh in general

They also have similar chemical properties

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

What properies is the lone pair in amines responsible for?

A

Their solubility in water and acting as bases

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

How is the bonding in amines similar to that of ammonia?

A

Both contain a lone pair

The remaining 3 bonds are localised covalent between either alyl groups or hydrogens

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

Why are amines soluble in water?

A

They have a lone pair on a hghly electronegative atom (nitrogen) and also have hydrogens bonded to it.

This means they can form hydrogen bonds with water molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why are larger amines (amines with larger alkyl groups) not as soluble in water (if at all)?

A

The large alkyl grups are less able to break the H-bonds between water molecules.

Because the enthalpy change to break these bonds > enthalpy change in formation of new bonds between alkyl groups + water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why are amines able to act as bases?

A

The lone pair on the nitrogen atom forms a dative covalent bond with H+ (by donating the electron pair)

This leaves an OH- making the solution alkaline

20
Q

What does the strength of an amine as a base depend upon?

A

The availability of the lone pair to bond with H+

The stability of the positive ion formed

The solubility of the amine and steric hindrance

21
Q

How do amines react with acids?

A

The amine accepts a H+ to form an alkyl-ammonium ion (e.g. ethylammonium) and water.

The reaction goes to completion

22
Q

How do amines react with water?

A

An alkyl-ammonium ion is formed as well as OH-

The reaction does not go to completion, instead reaching equilibrium

23
Q

Why do reactions between amides and acids go to completion but those between amines and water don’t?

A

Because the H3O+ ions in acidic solutions are more powerful H+ donors than water

24
Q

How can you tell that the reaction between an amine and an acid has gone to completion?

A

It loses its characteristic smell

25
Q

Why does having more alkyl groups make an amine more basic?

A

Alkyl groups tend to donate electrons and do so to the nitrogen.

This makes the lone pair more accessible and reduces steric hindrance.

26
Q

What is the general formula for primary amides?

A
27
Q

What is the general formula for secondary amides?

A
28
Q

What are amides?

A

Carboxylic acid derrivatives where the -OH group is replaced with -NH2

29
Q

How are amides made and why?

A

By reacting ammonia/amines with acyl chloride.

Carboxylic acids cannot be used as they don’t react to give amides

30
Q

What type of reaction occurs between ammonia/amines and acyl chloride?

What are the by-products?

A

A condensation reaction

The small molecule produced is HCl

31
Q

What type of amide does reacting ammonia and acyl chloride produce?

A

Primary amides

32
Q

What type of amide does reacting an amine and acyl chloride produce?

A

Secondary amides

33
Q

Why is condensation polymerisation called that?

A

Because the individual steps joining the molecules together are condensation reactions

34
Q

How are polyamides made and what links the monomers together?

A

Reacting a dicarboxylic acid and a diamine

The monomers are linked together by amide groups

35
Q

Why are polyamides called that?

A

Because the monomers are linked together by secondary amide groups

36
Q

What is another name for polyamides?

A

Nylons

37
Q

Why are acyl chlorides used instead of carboxylic acids when making nylons in the lab?

A

Because the reaction is slow otherwise and it is hard to demonstrate the process

38
Q

How are nylons named?

A

According to the number of carbon atoms in the monomers

The 1st digit is the no. in the diamine, the 2nd is the dicarboxylic acid

(This applies if 2 monomers are used)

(Think: a comes 1st, c 2nd)

39
Q

If a nylon only has 1 number after it what does that mean?

A

It has only been made from one monomer containing a diamide at one end and a dicarboxylic acid at the other

40
Q

What are acyl chlorides?

A

More reactive derrivatives of carboxylic acids

41
Q

What is the general formula of acyl chlorides?

A
42
Q

How are acyl chlorides named?

A

By replaicing the -oic with -oyl and ‘acid’ with ‘chloride’

43
Q

How are diacyl chlorides named?

A

Adding -dioyl instead of just -oyl

44
Q

How do acyl chlorides react with amines?

A

Vigourously to form amides:

RCOCl + R’NH2 → RCONHR’ + HCl

45
Q

How do acyl chlorides react with alcohols?

A

Vigourously to form esters:

CH3OH + C2H5COCl → C2H5COOCH3 + HCl

(Propanoyl chloride + methanol → methyl propanoate + hydrochloric acid)

A2 Chemistry (PL) (9 decks)

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