S5 - Unit 1 & 2 Flashcards
1
Q
How can alcohols be classified?
A
Depending on how many carbons are attached to a hydroxyl group
2
Q
What name is given to an alcohol with 1 carbon attached to the hydroxyl group?
A
Primary
3
Q
What name is given to an alcohol with 2 carbons attached to the hydroxyl group?
A
Secondary
4
Q
What name is given to an alcohol with 3 carbons attached to the hydroxyl group?
A
Tertiary
5
Q
What name is given to alcohols with more than one hydroxyl group?
A
Polyhydric alcohol
6
Q
How can alcohols be oxidised?
A
By adding oxygen or removing hydrogen
7
Q
How many steps can primary alcohols undergo in oxidation?
What happens in each step?
What is the product of each step?
A
- 2
- Removal of hydrogen and addition of
oxygen between carbon and hydrogen - Alcohol ~> aldehyde
Aldehyde ~> acid
8
Q
How many steps can secondary alcohols undergo in oxidation?
What happens in each step?
What is the product of each step?
A
- 1
- Removal of hydrogen
- Alcohol ~> ketone
9
Q
How many steps can tertiary alcohols undergo in oxidation?
What happens in each step?
What is the product of each step?
A
- 0
- N/A
- N/A
10
Q
How to aldehydes and ketones differ?
A
Aldehydes have the function group (carbonyl) always attached to the first carbon whereas in ketones the functional group (carbonyl) is attached to two other carbons
11
Q
What is the general formula for alkanals?
A
CnH2nO
12
Q
What is the general formula for alkanones?
A
CnH2nO
13
Q
What are the oxidising agents learned about?
A
- Acidified potassium dichromate solution
- Fehling’s solution
- Tollen’s reagent
14
Q
What are the observations made with each of the oxidising agents?
A
A.P.D.S = orange ~> green
F.S = Blue ~> orange
T.R = Colourless ~> silver
15
Q
What is the corresponding salt name for each carboxylic acid?
A
Methanoate
Ethanoate
Propanoate
Butanoate
Pentanoate
16
Q
What is the formula for a salt produced by a carboxylic acid and a metal?
A
CnH2n+1COO-__+
(__ = metal)
17
Q
How are esters produced?
A
By carboxylic acids undergoing condensation reactions with alcohols
18
Q
What is a condensation reaction?
A
When two molecules join together, usually in the presence of a catalyst, with the elimination of water or another simple molecule
19
Q
How do you name esters?
A
Alcohols name + carboxylic acid salt name
20
Q
What is the catalyst in a condensation and hydrolysis reaction?
A
Concentrated sulphuric acid
21
Q
What is the role of a wet paper towel when making esters?
A
Acts as a condenser
22
Q
Why is something used to cover the top of the test tube when making esters?
A
To contain any chemicals that may spurt out
23
Q
What is used to neutralise any remaining acid in the ester once it has been formed?
A
Sodium hydrocarbonate
24
Q
What properties do esters have?
A
- Usually have sweet smells
- More volatile than carboxylic acids
- Insoluble in water
- Much less polar than carboxylic acids
25
What are come uses of esters?
-Used as flavourings
- Used in perfumes
- Used as solvents
26
What is the functional group for aldehydes?
Carbonyl
27
What is the functional group for ketones?
Carbonyl
28
What does the carbonyl functional group structure look like?
.
|
----C=O
|
29
What is hydrolysis?
The opposite of condensation - when water is added to break up the molecule
30
What is the homologous series for the alkanones?
Ketones
31
What is the homologous series for the alkanals?
Aldehydes
32
What is the equation for carboxylic acids reacting with a metal?
Acid + metal ~> salt + hydrogen
33
What else is produced when an ester formed?
Water
34
What are diatomic elements?
Two atoms joined together by a shared pair of electrons
35
What are discrete molecules?
Small groups of atoms held together by strong covalent bonds inside the molecule and weak intermolecular forces between the molecule
36
What elements are most commonly discrete?
The diatomic elements
37
What are the only elements that can form covalent networks?
Carbon (in the form of diamond or graphite), boron and silicon
38
What are monatomic elements and what are examples?
Single, unattached atoms.
Elements in group 8 (they have a full outer shell of electrons
39
What happens when monatomic elements are cooled?
The atoms move closer and are held by week LDF's
40
What are London Dispersion Forces?
Weak, short lived bonds between atoms and molecules
41
How do LDF's occur?
Due to the positioning of the electrons in the outer shell
42
What happens if the electrons are unevenly distributed in the shells?
It can cause a temporary dipole allowing the atoms to be attracted to each other
43
What happens to the m.p and the b.p as you go down group 1 and why?
They decrease as the atoms become less tightly held together.
44
What can cause metallic bonds to get weaker?
If the delocalised electrons move further away from the nuclei of the positive ions
45
What happens to the m.p and b.p as you go down group 7 and why?
They increase as the LDF's between the molecules increases with atomic number.
46
What does an increased number in electrons mean?
An increase in the number of shells and therefore greater LDF's
47
What are polar covalent bonds?
When atoms with different electronegativities form covalent bonds
48
What are non-polar covalent bonds?
When atoms of the same electronegativities form covalent bonds
49
Which element (the one with less electronegativity or the one with greater) will have a slightly negative charge?
The element with a greater electronegativity
50
Which element (the one with less electronegativity or the one with greater) will have a slightly positive charge?
The element with a smaller electronegativity
51
Ionic bonds have ... electronegativites.
- Very high
- High
- Low
- No
High
52
Covalent bonds have ... electronegativites.
- Very high
- High
- Low
- No
No
53
Polar covalent bonds have ... electronegativites.
- Very high
- High
- Low
- No
Low
54
What are intramolecular forces?
Forces that hold the atoms within a molecule together
55
What are intermolecular forces?
Forces that exist between molecules
56
What are the three van der Waal's forces?
- LDF's
- Permanent dipole - permanent dipole (pd. pd.)
- Hydrogen
57
What do pd. pd forces occur between?
Atoms in compounds with different electronegativities
58
When does hydrogen bonding occur in compounds?
When N/O/F is linked to hydrogen
59
Why do some compounds containing hydrogen have higher boiling points than expected?
Because hydrogen bonding holds the molecules together more tightly than other van der Waal forces
60
What is viscosity directly proportional to?
The gfm of a molecule
61
What else, other than a high gfm, might cause a substance to be viscous?
Hydroxyl groups
62
What happens to the viscosity of a substance as the number of hydroxyl groups are increased?
It increases
63
What will dissolve polar and ionic substances?
Polar covalent molecules
64
What will dissolve non-polar substances?
A non-polar solvent
65
What does miscible mean?
Soluble
66
What does immiscible mean?
Insoluble
67
What does hydrogen bonding do the the miscibility of a substance?
Increases it
68
What are the 3 naturally occurring fats and oils?
- Animal fat
- Plant oil
- Marine Oil
69
What are examples of animal fats?
Lard and suet
70
What are examples of plant oils?
Sunflower and coconut
71
What are examples of marine oils?
Cod liver
72
What food group provides more energy per gram; fats or carbohydrates?
Fats
73
What properties do fats have?
Insoluble and group together
74
What molecule are fats and oils both based on?
Glycerol
75
What is the structure of glycerol?
76
What can each hydroxyl group in glycerol combine with?
- A carboxylic acid molecule
77
What name is given to the carboxylic acids that react with glycerol?
Fatty acids
78
How can you tell if a fatty acid is unsaturated or saturated?
If it is saturated the no. of H's is more than double the no. of C's
If it is unsaturated the no. of H's is less than double the no. of C's
79
What is produced when glycerol and carboxylic acids react?
Fats or oils
80
What reaction is undergone to produce a fat or oil?
Condensation
81
Complete the sentence
Fats and oils are ... of glycerol and fatty acids.
Esters
82
What do C=C introduce fats and oils to?
'Kinks'
83
Why are fats solid at room temperature?
They are compact and can pack closely together, resulting in a lot of LDF's
84
Why are oils usually liquid at room temperature?
They have a more irregular shape, meaning they cannot pack as closely together resulting in less LDF's
85
What is the structure of fats and oils and what makes them different?
- Oils have 'kinks' (irregular shape)
86
What is hydrogenation?
The catalytic addition of hydrogen to an unsaturated oil which hardens it and increases it's boiling and melting points
87
What determines the 'iodine number'?
The number of C=C in a fat or oil
(the greater the number of C=C, the greater the iodine number)
88
What are soaps?
Salts of fatty acids
89
How are soaps made?
The neutralisation of a fatty acid
90
What is the structure of a soap?
91
Complete the sentences:
The 'tail' of a soap is...
The 'head' of a soap is...
- Hydrophobic
- Hydrophilic
92
What properties do soaps have?
Hydrophobic, oil soluble and non-polar
93
How is grease removed with soap?
- The soaps hydrophobic covalent tail interacts with the grease
- Agitation and the strong attraction between the ionic head and the water dislodge the grease
- The grease droplets repel each other due to their negative heads and therefore don't join back together
94
What makes water 'hard'?
It contains Ca2+ and Mg2+ ions
95
What makes hard water different to water?
It doesn't form a lather with normal soaps and forms scum instead
96
How do you make an emulsifying agent?
By reacting glycerol with one fatty acid
97
What are all the different types of proteins?
- Muscle fibres
- Cell structure
- Hormones
- Binding proteins
- Structures ie: hair, nails
- All enzymes
98
How can proteins be classified?
According to their shape.
Either globular or fibrous
99
What does a fibrous protein consist of?
- Chains of interwoven polypeptides
- Polypeptide chains that are held together by hydrogen bonding
100
What is an example of fibrous proteins?
Hair
101
What are globular proteins?
Polypeptide chains coiled together in spherical shapes
102
What is an example of globular proteins?
Enzymes
103
What does an amino acid look like?
104
What type of link form between the two groups producing an amino acid?
An amide link
105
What does an amide link look like?
106
What is produced when 2 amino acids join together?
A polypeptide (protein) and Water
107
What type of reaction produces a polypeptide?
Condensation
108
What reaction break down proteins?
Hydrolysis
109
What type of reaction takes place in digestion?
Hydrolysis
110
What are essential amino acids?
Amino acids our body needs but cannot produce
111
What factors can denature an enzyme?
pH and temp.
112
What happens when an enzyme is denatured?
It stops working
113
What is the optimum temp. for enzymes in the human body?
40 degrees C
114
What features do soapless detergents have?
The head is hydrophilic/polar/ionic/can water soluble.
The tail is hydrophobic/non-polar/non-polar/ fat soluble.
115
How do emulsifiers prevent the separation of liquids?
Emulsifiers have two parts: a hydrophobic part and a hydrophilic part.
The hydrophobic part dissolves in non-polar liquids whilst the hydrophilic part dissolves in polar liquids.
116
What process makes soap?
Alkaline hydrolysis of fats/oils with sodium/potassium hydroxide
117
What is the process of making a soap called?
Saponification
118
What are essential oils?
Concentrated extracts of volatile, non-water soluble aroma compounds
119
What are essential oils used in?
Perfumes
Flavouring foods
Cleaning products
Cosmetic products
Preventing the oxidation of food
120
What makes up essential oils?
Terpenes
121
What makes up terpenes?
Isoprene units
122
What does an isoprene unit look like?
123
What is the product of the oxidation of terpenes?
Terpenoids
124
How many carbons are in an isoprene unit?
5
125
What are free radical scavenger?
Molecules which react with free radicals to form stable molecules and prevent chain reactions
126
What are examples of free radical scavengers?
Melatonin and vitamin E
127
What is the cause of sunburn?
UV light breaking bonds within molecules
128
What is formed when UV light breaks bonds?
Free radicals
129
What are the three steps of free radical chain reactions?
- Initiation
- Propagation
- Termination
130
What does the first stage of a free radical chain reaction involve?
131
What does the second stage of a free radical chain reaction involve?
132
What does the third stage of a free radical chain reaction involve?
133
How does sunscreen protect against UV light?
It reflects it away from our skin
134
What is meant by the term 'free radical'?
An atom with an unpaired electron
135
Why must titration reactions be carried out under acidic conditions?
To provide H ions
