Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Edexcel A Level Chemistry > ✅17 - Organic Chemistry II > Flashcards

✅17 - Organic Chemistry II Flashcards

1
Q

What type of isomerism is optical isomerism?

A

Stereoisomerism

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

What are structural isomers?

A

Compounds with the same molecular formula but with different structural formula

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

What are functional group isomers?

A

They differ because they have different functional groups

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

What are chain isomers?

A

Differ because they have different patterns of branching in their carbon chains

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

What are positional isomers?

A

Differ because the same functional group is attached to different carbon atoms in the chain

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

What are stereoisomers?

A

Have the same structural formula but differ because their atoms or groups are arranged differently in three dimensions

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

What are geometric isomers?

A

Differ because their atoms or groups are attached at different positions on opposite sides of a C-C double bond

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

What is chirality?

A

Two or more molecules that appear identical but cannot be superimposed onto one another.

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

What are chiral centres?

A

Carbons with four different atoms or groups attached

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

What is plane polarised light?

A

Light in which oscillations exist in planes at right angles to the direction of travel.

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

What can be used to convert unpolarised light into plane polarised light?

A

Materials such as Polaroid, which absorb all of the oscillations expect those in a single plane

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

What is polarimetry?

A

The use of a polarimeter to measure the amount of optical activity, if any, of a substance.

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

What is a monochromatic light source?

A

One of only one colour or frequency

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

What is a polariser?

A

A polarising filter that converts unpolarised light into plane polarised light

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

What happens in a polarimeter if a substance is optically active?

A

The plane of polarisation will be rotated so it is no longer vertical - Clockwise = dextrorotatory, Anticockwise = laevorotatory

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

What is the second polarising filter in a polarimeter called?

A

The analyser

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

What does the analyser do?

A

It is rotated to a position here the maximum light intensity can be seen. The angle of rotation is measured and quoted.

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

Do enantiomers have identical physical properties?

A

Yes - apart from the direction in which they rotate plane polarised light.

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

Do enantiomers have identical chemical properties?

A

Yes - apart from the way they react with enantiomers of other substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a racemic mixture?

A

One containing equal amounts of two enantiomers.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What does SN2 indicate?

A

S = substitution N= nucleophillic 2=bimolecular and second order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does SN1 indicate?

A

S = Substitution N = Nicleophillic 1 = unimolecular and first order

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How can optical activity be used as evidence for SN2?

A

Because of the inversion that occurs in the SN2 mechanism, the optical activity of the product is different to that of the reactant. If the reactant is dextrorotatory, the product will be laevorotatory and vice versa.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How can optical activity be used as evidence for SN1 mechanisms?

A

If the reaction is via SN1, there will be no optical activity in the product.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is a carbonyl group?
C=O
26
What compounds are classified as carbonyl compounds?
Aldehydes and Ketones
27
What defines an aldehyde?
A hydrogen joined to a carbonyl group
28
What defines a ketone?
If there are only hydrocarbon groups joined to the carbonyl
29
How do carbonyl groups affect bonding?
They form polar bonds, because oxygen is much more electronegative than carbon
30
What are the physical properties on aldehydes?
The have distinctive smells - short carbon chains = unpleasant, long carbon chains = pleasant
31
What are the relative boiling points of aldehydes, ketones, alcohols and alkanes?
Alkanes < Aldehydes < Ketones < Alcohols
32
Why do aldehydes and ketones have lower boiling points than alcohols?
They have intermediate intermolecular forces, only dipole dipole, so hydrogen bonds are not able to form because all the hydrogen atoms are attached to carbon atoms only.
33
How soluble are aldehydes and ketones?
Smaller aldehydes and ketones are soluble because they can form hydrogen bonds with water. Solubility decreases with chain length
34
What can aldehydes and ketones be reduced to?
Alcohols
35
What is the reagent for reduction of aldehydes and ketones?
Lithium Aluminium Hydride
36
How are reductions of carbonyl compounds carried out?
With both the carbonyl and reducing agent in dry ether
37
What reagents can be used to oxides aldehydes to carboxylic acids?
Acidified potassium dichromate, Fehling’s, Benedict’s, Tollens’
38
What is the colour change for acidified potassium dichromate?
Orange —-> green
39
What is the colour change for Fehling’s?
Deep blue solution —-> red precipitate
40
What is the colour change for Benedict’s?
Deep blue solution —-> red precipitate
41
What is the colour change for Tollens’?
Colourless solution —-> Silver mirror
42
How can you distinguish between aldehydes and ketones?
Aldehydes react with Benedict’s, Fehling’s and Tollens’, ketones do not
43
How do aldehydes and ketones react with iodine?
Carbonyls with CH3CO react with iodine to for triiodomethane - a yellow precipitate
44
What is the equation for the reaction between a carbonyl compound and iodine?
COCH3 + 3I2 + 4OH- ——> RCOO- + CHI3 + 3I- + 3H20
45
How can Brady's reagent be used to distinguish between aldehydes and ketones?
An orange precipitate forms if a carbonyl is present The precipitate can be purified by re-crystallisation Each different carbonyl give a crystal with a different melting point If the melting points are measured and compared to a table of known values, the compound can be identified
46
Under what conditions do reactions with hydrogen cyanide occur?
In aqueous alkaline solution containing potassium cyanide
47
What is the equation for addition of HCN to propanal?
CH3CH2CHO + HCN ----> CH3CH3CH(OH)CN
48
What is the equation for addition of HCN to butanone?
CH3COCH2CH3 + HCN ----> CH3C(CN)(OH)CH2CH3
49
What type of mechanism is the addition of hydrogen cyanide to a carbonyl?
Nucleophilic addition
50
What does the addition of HCN involve?
The hydrogen atom attaches to the oxygen of the carbonyl and a cyanide group attaches to the carbon of the carbonyl group
51
How many steps are in the nucleophillic addition of HCN?
Two , and an intermediate is formed
52
How can optical activity be used as evidence for the mechanism of addition of HCN?
The arrangement of the two atoms or groups attached to the C=O is planar, so the cyanide ion can attack from above or below. Creates a chiral carbon, but with a equal amounts of dextrorotatory and laevorotatory enantiomers, no optical activity.
53
What is the common name for methanoic acid?
Formic acid
54
How is the charge distributed in a carboxylate (COO-) ion?
Evenly
55
What are the physical properties of carboxylic acids?
They have distinctive smells and sour tastes
56
What are the relative boiling points for carboxylic acids?
Very high
57
Why do carboxylic acids have high boiling points?
They have three polar bonds in the carboxylic acid group which give them strong intermolecular forces and hydrogen bonding
58
How does the length of the carbon chain in a carboxylic acid affect the boiling point?
The longer the chain, the higher the boiling point because London forces increase
59
Why do shorter carboxylic acids form dimers?
In the absence of a solvent, two molecules hydrogen bond with one another
60
What type of carboxylic acids are soluble in water?
Shorter chain ones, as they can form hydrogen bonds with water
61
How does chain length affect solubility in carboxylic acids?
Solubility decreases with increasing chain length
62
What are the two main methods of producing carboxylic acids?
Oxidation and hydrolysis
63
What are the conditions for oxidation of a primary alcohol or aldehyde to form a carboxylic acid?
Acidified potassium dichromate (VI) and reflux
64
What is the equation for the oxidation of propan-1-ol to propanoic acid?
CH3CH2CH2OH + 2[O] ----> CH3CH2COOH + H20
65
What is the equation for the oxidation of propanone to propanoic acid?
CH3CH2CHO + [O] ----> CH3CH2COOH
66
What can be hydrolysed to from a carboxylic acid?
Nitriles and organic compounds containing CN group
67
What are the conditions for hydrolysing nitriles to form carboxylic acids?
Reflux with either a dilute acid or aqueous alkali
68
What is the equation for the hydrolysis of propanenitrile with dilute acid?
CH3CH2CN + H+ + 2H2O ----> CH3CH2COOH + NH4+
69
What is the equation for the hydrolysis of butanenitrile with aqueous alkali?
CH3CH2CH2CN + OH- + H2O ----> CH3CH2CH2COO- + NH3 Butanoate ion then converted into acid by adding dilute acid: CH3CH2CH2COO- + H+ ----> CH3CH2CH2COOH
70
What are the four main reactions of carboxylic acids?
Reduction Neutralisation Halogenation Esterification
71
What is the product of neutralisation of a carboxylic acid?
A carboxylate salt
72
Which reducing agent is used to reduce carboxylic acids?
Lithium aluminium hydride
73
What is the equation for the neutralisation of ethanoic acid using sodium hydroxide?
CH3COOH + NaOH ----> CH3COONa + H2O
74
What is the product of halogenation of a carboxylic acid?
Acyl chloride
75
What are the conditions for halogenation of carboxylic acids?
Phosphorus (V) chloride and anhydrous conditions
76
Why are anhydrous conditions used for halogenation of carboxylic acids?
Because both the reagent and the acyl chloride react vigorously with water
77
What is the equation for the halogenation of propanoic acid?
CH3CH2COOH + PCl5 ----> CH3CH2COCl + POCl3 + HCl
78
What are the conditions for esterification of carboxylic acids?
Alcohol and a small amount of acid catalyst, often conc H2SO4
79
What is the equation for the esterification of mathanoic acid with ethanol?
HCOOH + CH3CH2OH HCOOCH2CH3 + H2O
80
What is the general formula for acyl chlorides?
RCOCl
81
What are acyl chlorides prone to?
Nucleophillic attack, as the carbon is joined to two electronegative atoms, so is electron deficient
82
How do acyl chlorides react with cold water?
Vigorously, forming a carboxylic acid and releasing hydrogen chloride gas, appearing as misty fumes
83
What is the equation for the reaction of ethanoyl chloride and water?
CH3COCl + H2O ----> CH3COOH + HCl
84
How do acyl chlorides react with alcohols?
They readily react with ethanol to form ab ester and hydrogen chloride gas
85
What is the equation for the reaction of ethanoyl chloride with ethanol?
CH3COCl + CH3CH2OH ----> CH3COOCH2CH3 + HCl
86
How do acyl chlorides react with concentrated ammonia solution?
In two steps, an NH2 group joins with the carbonyl group to produce an amide as well as ammonium chloride
87
What is the equation for the reaction between ethanoyl chloride and conc ammonia?
CH3COCl + 2NH3 ----> CH3CONH2 + NH4Cl
88
How do acyl chlorides react with primary amines?
One H form the amine react with Cl to form HCl and the rest of the compound is attached to the carbonyl group
89
What is the equation for the reaction between ethanoyl chloride and methylamine?
CH3COCl + CH3NH2 ----> CH3CONHCH3 + HCl
90
Why don'y acyl chlorides react with tertiary amines?
There is no H to react with the Cl to form HCl
91
What are the physical properties of esters?
Colourless liquids with low melting and boiling points, insoluble in water, no hydrogen bonding. Generally pleasant smell.
92
What are the two types of hydrolysis of esters?
Hydrolysis in acidic solution and in alkaline solution
93
What is the equation for hydrolysis of ethyl ethanoate with a sulfuric acid catalyst?
CH3COOCH2CH3 + H2O CH3COOH + CH3CH2OH
94
What is the equation for the hydrolysis of methyl propanoate in alkaline solution?
CH3CH3COOCH3 +NaOH ---> CH3CH2COO- + Na+ + CH3OH
95
What is saponification?
Alkaline hydrolysis of esters to form an alcohol and a stearate, commonly used in soaps
96
What is condensation polymerisation?
Each time two monomer molecules join together, another small molecule is formed Usually two different monomers react together
97
What is the small molecule formed during condensation polymerisation?
Often water
98
How are polyesters formed?
Through condensation polymerisation
99
What are the monomers of polyesters?
A diol and a dicarboxylic acid

Edexcel A Level Chemistry (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions