Unit 2 - Nature's Chemistry Flashcards
(141 cards)
1
Q
1 mol
A
Formula mass in grams
2
Q
Molar volume
A
The volume occupied by 1mol of gas at a given temperature and pressure.
3
Q
Excess reactions
A
Moles, ratio, conclusion
4
Q
Equilibrium
A
Equal rates of forward and backwards reactions. Constant concentrations.
5
Q
% yield
A
Measures efficiency.
6
Q
Atom economy
A
GFM x moles = mass
Plug in mass
7
Q
Bond enthalpy
A
The energy required to break 1 mol of bonds between two atoms.
8
Q
Bond enthalpy formula
A
ΔH = ΔEHbonds broken + ΔEH bonds made
9
Q
Enthalpy definition
A
The measure of energy stored in a chemical.
10
Q
Catalysed PE diagrams
A
Lower activation energy
11
Q
Molar volume is _____ for all gasses at the same pressure and temperature.
A
The same
12
Q
Le Chateliers Principle
A
An equilibrium will move to undo any change imposed upon it by temporarily favouring either the forward or backward reaction until a new equilibrium position is reached.
13
Q
Steps to balancing ion-electron redox equations
A
- Balance main element
- Add water
- Add hydrogens
- Add electrons
14
Q
An oxidising agent is..
A
a substance that accepts electrons
15
Q
A reducing agent is…
A
a substance that donates electrons
16
Q
Reducing agents have ___ electronegativity values.
A
low
17
Q
Oxidising agents have ___ electronegativity values
A
high
18
Q
Carboxylic acids are polar molecules and can therefore…
A
Hydrogen bond
19
Q
Hydrogen peroxide is effective as..
A
Bleach
20
Q
Unsaturated compounds ____ bromine water
A
rapidly decolourise
21
Q
Saturated compounds ____ bromine water
A
Do nothing in
22
Q
Factors on solubility, BP and MP
A
- hydrogen bonding
- PDs
- molecular size for LDFs
- polarities of solute and solvent
23
Q
Smaller non-polar hydrocarbons like ethane are ______ volatile and have ______ BPs
A
More, lower
24
Q
Smaller non-polar hydrocarbons like ethane are more volatile and have lower BPs because…
A
They have more electrons for LDFs
25
non-polar hydrocarbons ____ dissolve in water
Do not
26
Alcohol general formula
Cn H2n+1 OH
27
Primary alcohols
OH is joined to the end of the carbon chain
28
Secondary alcohols
Joined to a carbon in the middle of a carbon chain
29
Tertiary alcohols
Joins to a carbon which is attached to three other carbons
30
Alcohols conform hydrogen bonds because..
The -OH group makes them polar
31
More hydrogen bonds make a liquid more viscous because..
PD-PD interactions mean stronger intermolecular forces
32
Carboxylic acids react with
Bases
33
Metal oxide + carboxylic acid
salt + water
34
metal hydroxide + carboxylic acid
salt + water
35
metal carbonate + carboxylic acid
Salt + water + CO2
36
Acids contain
More H+ ions
37
Bases contain
More OH¯ ions
38
Carboxylic acids are acidic because they can break up...
to leave hydrogen ions in an aqueous solution
COOH becomes COO and H+
39
When salts are formed the H+ part of the acid
Is replaced by an alkali metal
40
lithium oxide + ethanoic acid
Lithium ethanoate + water
41
Potassium hydroxide + methanoic acid
Potassium methanoate + water
42
Calcium carbonate + propanoic acid
Calcium propanoate + water + CO2
43
44
In a condensation reaction
two molecules are joined together with the elimination of a smaller molecule
45
An ester link is formed by
A hydroxyl group and a carboxyl group
46
Esters are formed by
A condensation reaction between an alcohol and a carboxylic acid
47
Hydrolysis
A molecule is broken down into smaller molecules by reacting with water
48
Edible fats and oils are Esters formed by
The condensation of glycerol + three carboxylic acid molecules
49
Glycerol's molecular formula
Propane-1,2,3-triol
50
The greater the degree of saturation in a fat, the ____ the MP, because..
Higher, double bonds prevent molecules packing closely together and weaken the van der waals forces
51
Biological uses of fats
- a concentrated source of energy
- transporting fat soluble vitamins in the body
52
Ethanol + ethanoic acid
ethyl ethanoate (ester) + water
53
Methanol + ethanoic acid
Methyl ethanoate (ester) + water
54
Ethanol (alcohol) + butanoic acid (carboxylic acid)
Ethyl butanoate (ester) + water
55
Ester uses
- Flavours
- solvents for np compounds
56
Ester BP
Low
57
Ester hydrolysis
When an ester reacts with water and breaks down to form an alcohol and a carboxylic acid
58
Forming an Ester is a _____ reaction
Condensation
59
Breaking up an Ester is a ______ reaction
Hydrolysis
60
Edible fats and oils are also known as
tri-esters
61
Facts are formed by reaction between
Propan-1,2,3-l (glycerol) and 3 carboxylic acid molecules
62
Carboxylic acids that react to form fats are called
Fatty acids
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Fats are formed from _____ fatty acids
Saturated
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Oils are formed from _____ fatty acids
Unsaturated
65
Saturated fats are (state)
Solid
66
Oils have a lower melting point than fats because
Double bonds prevent them packing tightly, weakening intermolecular bonds
67
One way to test degree of unsaturation in oils
React with bromine water, the more solution that can be reacted, the more double bonds
68
Esters are soluble / insoluble in water
Insoluble
69
Fats are formed from
Saturated fatty acids and glycerol
70
Oils are formed from
Unsaturated fatty acids and glycerol
71
Edible fats and edible oils are what kind of homologous series
Esters
72
The hydrolysis of edible fats and edible oils produces
Glycerol and carboxylic acids (fatty acids)
73
The hydrolysis of edible fats and edible oils with an alkali eg. NaOH produces
Salts from the fatty acids
74
Salts produced from the fatty acids are also known as
Soaps
75
Fatty acids vs standard carboxylic acids
Fatty acids have long hydrocarbon chains
76
Alkaline hydrolysis of a fat produces
Glycerol + a soap
77
The salt of a carboxylic acid
Soap
78
The heads of soap molecules are
Hydrophilic, ionic and water soluble
79
The tails of soap molecules are
Hydrophobic and oil soluble
80
Steps to the functions of soaps
1. The hydrophobic tail dissolves in the grease
2. The grease now has a covering of negative charge
3. It can form globules when agitated
4. These globules are attracted to the water and can be washed away
81
Hard water contains
High levels of dissolved minerals such as calcium and magnesium ions
82
What is formed when soap is dissolved in hard water
Scum, an insoluble precipitate
83
Soaps are
Sodium salts of carboxylic acids with long hydrocarbon chains
84
Detergents are
Sodium or potassium salts of sulphonic acids with long hydrocarbon chains
85
Chemical formula structure of a soap molecule
R-COOH-K
or
R-COOH-Na
86
Chemical formula structure of a fatty acid molecule
R-COOH
87
Chemical formula structure of a fatty acid molecule to form a detergent
R-SO4
Any ion at the head, but not carboxylate (COO¯)
88
Emulsifier examples
Mono-glycerides and di-glycerides
89
Enzymes are
Proteins which act as biological catalysts
90
What building blocks are proteins formed from
Amino acids
91
Amino acids functional groups
Amino and carboxyl (NH2 and COOH)
92
Formation of proteins
H on a NH2 group and OH on a COOH joined in long chains
93
Peptide link formula
C=O(-NH)
94
Types of amino acids
Essential, non-essential
95
Digestive process to produce amino acids
Enzyme hydrolysis of protein
96
What is eliminated in the formation of amino acids
Water
97
Another name for amide link
Peptide link
98
Structure of an amide link
C=O
|
N-
|
H
99
Significance of nitrogen in amino acids and proteins
NH allows for hydrogen bonding
100
Describe denaturing proteins
Hydrogen bonds holding proteins together break causing the twisted structure to unfold and shape to change
101
Proteins can form hydrogen bonds because
They contain an
-NH
102
What kind of reaction is splitting up a protein
Hydrolysis
103
Oxidation is ____ of hydrogens
Loss
104
Aldehydes or alcanals are produced by the oxidation of
Primary alcohols
105
Ketones are produced by the oxidation of
Secondary alcohols
106
CH3 CH2 OH (ethanol) is oxidised to
CH3 CHO (ethanal)
107
CH3 CH2 CH2 OH is oxidised to (propan-1-ol)
CH3 CH2 CHO (propanal)
108
Oxidation of secondary alcohols produces
Ketones
109
CH3 CH(OH) CH3 (propan-2-ol) is oxidised to
CH3 C=O CH3 (propanone)
110
CH3 CH2 CH(OH) CH3 (butan-2-ol) is oxidised to
CH3 CH2 C=O CH3 (butanone)
111
Aldehyde suffix
-anal
(bond at the back of molecule, back -> anal)
112
Ketone suffix
-one
(ketones -> alkanones)
113
When primary alcohols are oxidised they produce
Aldehydes
114
When secondary alcohols are oxidized they produce
Ketones
115
Carbonyl group (C=O) is found on what type of molecule
Aldehydes and ketones
116
Systematic name of CH3 CH2 C=O CH(CH3) CH2 CH2 CH2 CH3
4-methyl octan-3-one
117
Ketones _____ oxidise
Don't
118
Three most common oxidizing reagents
- Fehling's solution
- Tollen's reagent
- acidified potassium dichromate
119
Between pentan-2-one an ethanal, which would react with Tollen's reagent
Ethanal, because it is an aldehyde and can therefore be oxidised
120
Oxidizing an alkanal involves
The addition of an oxygen
121
The oxidation of aldehydes produces
Carboxylic acids
122
Butanal oxidizes to
Butanoic acid
123
-C=0
|
H
Oxidises to
-C=O
|
OH
124
Oxidation involves either adding ____ or removing ____
Oxygens, hydrogens
125
The hydrogen oxygen ratio of a compound can be used to show
Whether oxidation or reduction has occurred
126
In the H:O ratio, more Oxygen means
Oxidation
127
In the H:O ratio, more H means
Reduction
128
Primary alcohols oxidise to ___ which oxidise to ___
Aldehydes, carboxylic acids
129
Which compounds are not readily oxidised
Ketones and tertiary acohols
130
Carboxylic acids can undergo reduction which involves
The removal of an oxygen from the OH group
131
Functional groups resulting in polar molecules
Hydroxyl, carbonyl, carboxyl, amino and amide
132
Hydroxyl, carbonyl, carboxyl, amino and amide molecular formula
-OH
-C=O
-C=O(OH)
NH2
CONH
133
Antioxidants are _____ to _______
Oxidised, prevent unwanted oxidation reactions happening
134
Changes oxidation can make to foods
- reacting with water to remove vit c
- making aldehydes into acids
- making fats go rancid
135
Terpenes are found in _____ and formed from ______
Essential oils, isoprene units
136
Isoprene formula
C5H8 (2 double bonds)
( 2-methyl-1,3-butadiene)
137
Free radicals are
Atoms or molecules which are highly reactive due to the presence of unpaired electrons
138
Steps of a free radical reaction, 1
1. Initiation
Free radicals are formed by the splitting of a diatomic halogen molecule by UV light
139
Steps of a free radical reaction, 2
2. Propagation
A free radical steals a hydrogen from an alkane
A free radical of that alkane is formed
That free radical then steals a halogen from a diatomic molecule, leaving another halohen free radical
The cycle continues
140
Steps of a free radical reaction, 3
3. Termination
- Halogen free radicals can join together
- Alkane free radicals can join together
- An alkane free radical can join with a halogen free radical
141
Free radical scavengers are
Molecules that easily react with free radicals as Vitamin C, added to cosmetic products
