Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

CHEM > topic 17 > Flashcards

topic 17 Flashcards

(70 cards)

Start Studying
1
Q

what are optical isomers

A

mirror images of each other

non super imposable

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

what is a chiral molecule

A

one that has 4 different groups attached

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

what is an enantiomer

A

when the groups of a chiral molecule can be arranged in 2 different ways creating 2 different molecules
mirror image
non super imposable

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

what do optical isomers do

A

rotate the plane of plane polarised light

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

what is a racemic mixture

A

a mixture of both optical isomers

contains equal quantities of each enantiomer of a chiral compound

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

do racemic mixtures rotate the plane of plane polarised light

A

no

the 2 enantiomers cancel each others light rotating effect

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

does sn1 lead to racemic mixture forming

A

yes

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

does sn2 lead to racemic mixture forming

A

no

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

why does sn1 lead to racemic mixture forming

A

in step 1 a group breaks off causing molecule to be planar

now nucleophile can attack from either side resulting in 2 optical isomers

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

what does sn2 produce

A

a single enantiomer

nucleophile has to attack on the opposite side to where the group leaves

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

aldehyde group

A

c double bond o
end of molecule
ends in -al

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

what is a carbonyl

A

c double bond o

aldehydes and ketones

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

what is a ketone

A

c double bond o
middle of molecule
end in -one

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

why do carbonyls have low BP

A

don’t have a polar OH bond

can’t form H bonds with other aldehyde or ketone molecules

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

what happens when carbonyls are in water

A

both aldehydes and ketones form H bonds with water
o from carbonyl joins with an H on water molecule

small carbonyls dissolve
larger ones don’t

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

how to test for an aldehyde

A

tollens/ silver mirror
fehlings
acidified dichromate (VI) ions

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

state the procedure for the tollens/ silver mirror test

A

tollens reagent is a colourless solution of silver nitrate dissolved in aq ammonia
heated in a test tube with an aldehyde
after a few minutes a silver mirror forms

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

when heating organic compounds why shouldn’t you heat them directly over the flame

A

most of them are flammable

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

state the procedure for the fehlings test

A

fehlings is a blue solution of Cu2+ dissolved in NaOH
heat with an aldehyde
turns to brick red ppt

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

state the procedure for the acifdified dichromate testing for aldehyde

A

if you heat aldehyde with acidified dichromate you form a carboxylic acid
should see colour change
orange to green

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

in oxidation reactions what do you use to show oxidation

A

[O]

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

in reduction reactions what do you use to show reduction

A

[H]

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

state a reducing agent

A

lithium aluminium hydride

LiAlH4

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

an aldehyde reduces to …

A

a primary alcohol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
a ketone reduces to ...
a secondary alcohol
26
how does HCN react with carbonyls | and what does it form
nucleophilic addition forming a hydroxynitrile
27
what precaution should you take with the HCN reaction
in a fume cupboard, coat, gloves, goggles | HCN is a highly toxic gas
28
how to test for a carbonyl group
2, 4 DNP | forms an orange ppt if carbonyl group is present
29
after testing with 2 4 DNP for carbonyl how could you then identify the exact compound
recrystallisation | then measure melting point and compare it to a table of known melting points
30
how to test for a methyl group | iodoform test
the methyl groups react when heated with iodine smell fruity/ nail polish remover yellow ppt formed
31
what is a carboxylic acid
COOH end of molecule ends in -oic acid weak acid and therefore forms carboxylate ions and H+
32
solubility of carboxylic acids
very soluble can form H bonds with each other and water molecules the longer the carbon chain the less soluble
33
BP of carboxylic acids
high BP | can form H bonds with each other- very strong
34
how are carboxylic acids formed from aldehydes
full oxidation of primary alcohols | using acidified dichromate
35
how are carboxylic acids formed from from nitriles
hydrolysis of nitriles add water and HCL to nitrile HUR end up with carboxylic acids and NH4Cl
36
what do carboxylic acids form when they they react with bases
salts | acid + base --> salt + water
37
what do carboxylic acid salts end in
-oate
38
carboxylic acids react with carbonates or hydrogen carbonates to form what
salt carbon dioxide water
39
carboxylic acid reduced to
a primary alcohol
40
how to get an acyl chloride
carboxylic acid + PCl5
41
carboxylic acid + PCl5 forms what
acyl chloride
42
what makes esters distinctive
smell fruity
43
what is the functional group of an ester
-COO-
44
what are the 2 parts of an ester
an alcohol | carboxylic acid
45
how to name the ester
``` look at the alcohol group eg ethanol (ethyl group) ``` then look at carboxylic acid eg ethanoic acid (ethanoate) ester called ETHYL ETHANOATE
46
what happens with writing the formula for an ester
opposite to naming | acid then alcohol
47
how to form an ester from a carboxylic acid
esterification heat carboxylic acid with alcohol in presence of an acid catalyst (H2SO4 or HCl) form an ester and water
48
how to break up esters
hydrolysis reactions either acid hydrolysis or base hydrolysis
49
acid hydrolysis of esters
``` reflux ester with acid splits ester into a carboxylic acid and alcohol reversible reaction complete reaction slower ```
50
base hydrolysis of esters
``` reflux ester with alkali (NaOH) forms carboxylate ion and alcohol irreversible reaction complete reaction faster ```
51
what is a diol
2 -OH groups
52
how to form polyesters
a diol and a dicarboxylic acid
53
what is a dicarboxylic acid
contains 2 COOH groups
54
features of polyester
strong | flexible
55
uses of polyesters
clothes | carpets
56
acyl chloride functional group | ∧ naming
- COCl | - oyl chloride
57
formula for an acyl chloride
CnH2n-1 OCl
58
acyl chlorides react with cold water
COLD WATER vigorous reaction producing carboxylic acid
59
acyl chlorides react with alcohols
ROOM TEMP vigorous reaction producing an ester
60
acyl chlorides react with concentrated ammonia
ROOM TEMP violent reaction producing an amide
61
acyl chlorides react with amines
ROOM TEMP violent reaction producing N substituted amide
62
state a observation when PCl5 reacts with OH-
steamy white fumes
63
what is a reagent/condition needed for esterification
concentrated H2SO4
64
products of esterification
ester and water
65
can a secondary alcohol be oxidised to a carboxylic acid
no only a ketone
66
what do primary alcohols oxidise to
aldehydes and carboxylic acids
67
how to test for a methyl ketone | And what is a methyl ketone
has a methyl group next to the ketone group add iodine and NaOH heat pale yellow ppt forms if present (CHI3) products - carboxylate ion, Na+, CHI3 (ppt)
68
how to test for an OH group
use PCl5 | should see steamy white fumes
69
oxidation of primary alcohol reagents and conditions
dilute h2so4 potassium dichromate HUR
70
difference in reaction when using alcoholic KOH aqueous KOH
alcoholic is elimination reaction get rid of halogen and hydrogen form water and KX X=halogen aqueous is subsitution

CHEM (4 decks)

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