Unit 2 - Nature’s Chemistry Flashcards
Unit 2 - Alcohols, Aldehydes, Ketones, & Carboxylic Acids, Systematic Carbon Chemistry, Esters, Fats & Oils, Proteins, Oxidation of Food, Fats, Oils, Soaps, & Emulsions, and Fragrances
1
Q
Define, ‘Hydrocarbon’?
A
Compounds made from carbon and hydrogen only
2
Q
Define, ‘Homologous Series’?
A
A family of compounds with the same general formula, similar chemical properties and patterns in physical properties
3
Q
Define, ‘Isomers’?
A
Molecules with the same molecular formula but different structural formula
4
Q
Define, ‘Saturated’?
A
A molecule that contains single carbon to carbon bonds
5
Q
Define, ‘Unsaturated’?
A
A molecule that contains double carbon to carbon bond(s)
6
Q
Describe, how to test for ‘Unsaturation’?
A
The bromine water test, where you mix bromine solution with a Alkane or Alkene, with Alkanes the solution will remain orange but in Alkenes the solution will decolourise
7
Q
Are Alkanes saturated or unsaturated?
A
They are saturated as they contain only single carbon to carbon bonds
8
Q
Are Alkenes saturated or unsaturated?
A
They are unsaturated as they contain double carbon to carbon bond(s)
9
Q
Are Cycloalkanes saturated or unsaturated?
A
They are saturated as they contain only single carbon to carbon bonds
10
Q
Are Alkynes saturated or unsaturated?
A
They are unsaturated as they contain triple carbon to carbon bond(s)
11
Q
What’s the general formula of Alkanes?
A
CnH2n + 2
12
Q
What’s the general formula of Alkenes?
A
CnH2n
13
Q
What’s the general formula of Cycloalkanes?
A
CnH2n
14
Q
What’s the general formula of Alkynes?
A
CnH2n - 2
15
Q
Are Alkanes polar or non polar?
A
Non polar
16
Q
Are Alkenes polar or non polar?
A
Non polar
17
Q
Are Cycloalkanes polar or non polar?
A
Non polar
18
Q
What happens when Alkanes increase in size?
A
The boiling point increases due to there being more electrons, and therefore stronger LDFs
19
Q
Name the ‘Addition Reactions’?
A
Halogenation, Hydration, Hydrogenation and Polymerisation
20
Q
What are the three classification of alcohols?
A
Primary, Secondary and Tertiary
21
Q
How do you identify ‘Primary alcohols’?
A
The hydroxyl group is connected to 1 other carbon atom and is joined at the end of a carbon chain
22
Q
How do you identify ‘Secondary alcohols’?
A
The hydroxyl group is attached to 2 other carbons and is joined to an intermediate carbon in the chain
23
Q
How do you identify ‘Teriary alcohols’?
A
The hydroxyl group is bonded to 3 other carbons and is joined to a carbon within the chain which also has a branch
24
Q
Define, ‘Diol’?
A
An alcohol that contains 2 hydroxyl groups
25
Define, ‘Triol’?
An alcohol that contains 3 hydroxyl groups
26
Are Alcohols polar or non polar?
Polar
27
Explain the trend in ‘Diol’ and ‘Triol’ alcohols?
The greater number of hydrogen groups the stronger the hydrogen bonding therefore they have higher melting points + boiling points, are more viscous and soluble in water, but the longer the chain the less water soluble the alcohol is
28
Define, ‘Oxidation’?
An increase in the Oxygen to Hydrogen ratio
29
Define, ‘Reduction’?
A decrease in the Oxygen to Hydrogen ratio
30
What do Primary alcohols oxidise to form?
Aldehydes, and then oxidised further to Carboxylic Acids
31
What do Secondary alcohols oxidise to form?
Ketones, and they don’t oxidise further
32
What do Tertiary alcohols oxidise to form?
They don’t oxidise
33
What functional group do Aldehydes and Ketones have?
Carbonyl, -CO
34
What’s the general formula of Aldehydes?
CnH2nO
35
What’s the general formula of Ketones?
CnH2nO
36
“Aldehydes and Ketones are _______ of each other as they have the same general formula”
Aldehydes and Kentones are isomers of each other as they have the same general formula
37
What Oxidising Agent(s) can be used to distinguish ‘Aldehyde’ from a ‘Ketone’?
Fehling/Benedict’s solution, Tollen’s reagent, and Acidified dichromate
38
What colour change occurs between an Aldehyde and ‘Fehling/Benedict’s solution’?
Blue to a Brick-red precipitate being formed
39
What colour change occurs between an Aldehyde and ‘Tollen’s Reagent’?
Colourless to Silver mirror colour
40
What colour change occurs between an Aldehyde and ‘Acidified sodium dichromate’?
Orange to Green
41
What does a Metal Oxide + Carboxylic Acid produce?
A salt and water
42
What does a Metal Hydroxide + Carboxylic Acid produce?
A salt and water
43
What does a Metal Carbonate + Carboxylic Acid produce?
A salt, water, and carbon dioxide
44
Describe, the ‘Oxidation of Food’?
The oxygen from the air causes the oxidation of food which results in a rancid flavour
45
Define, ‘Antioxidant’?
A molecule that can prevent unwanted oxidation from occurring as they are easily oxidised
46
Define, ‘Condensation’?
A reaction in which 2 molecule are joined together with the elimination of a small molecule (usually water)
47
Explain how ‘Esters’ are formed?
They are formed when an condensation reaction occurs between a Carboxylic Acid reacts with an Alcohol
48
What does an Ester link look like?
-COO
49
Are Esters polar or non polar?
Polar
50
What forces exist between Ester molecules?
London Dispersion Forces
51
Explain the trend in Formula mass in Esters?
As formula mass increases the boiling point increases
52
When making an Ester, why do you use hot water instead of a bunsen burner?
Alcohol is highly reactive/flammable
53
When making an Ester, why do you use concentrated Sulfuric Acid?
It acts as an catalyst
54
When making an Ester, why do you use a wet paper towel?
To act as an condenser to prevent volatile reactants escaping
55
What does a Condensation reaction between a Carboxylic acid + Alcohol produce?
An ester and water
56
What is the opposite of a ‘Condensation Reaction’?
Hydrolysis
57
What is the opposite of a ‘Hydrolysis Reaction’?
Condensation
58
Define, ‘Hydrolysis’?
The breaking down of a larger molecule into smaller molecules using water
59
What does a Hydrolysis reaction between an Ester + Water produce?
A carboxylic acid and alcohol
60
What's the systematic name of 'Glycerol'?
Propane-1,2,3-triol
61
Explain how ‘Fats and Oils’ are formed?
A condensation reaction between 3 fatty acids and glycerol
62
Are Fats and Oils polar or non polar?
Non polar
63
“Fats are _____ at room temperature.”
Fats are solid at room temperature
64
“Oils are ______ at room temperature.”
Oils are liquid at room temperature
65
Explain, 'Oil hardening'?
Addition reactions between the double bonds and hydrogen can take place
66
Saturated fats are packed closely together, what does this do?
It allows for the formation of stronger LFDs and higher melting points
67
Unsaturated Oils cause ‘kinks’ in the chain, what does this do?
It prevents the packing of layers
68
"Fats and oils are a ____________ ______ __ _____"
Fats and oils are a concentrated source of energy
69
What are Fats and Oils essential for?
The transport and storage of fat-soluble vitamins in the body
70
Explain how ‘Soaps’ are formed?
A hydrolysis reaction between fats and oils
71
Describe, the structure of ‘Soaps’?
Soap has a Hydrophilic head that is water soluble, has a negative charged carboxylate group and is there ionic. Soap also has a Hydrophobic tail that is oil soluble
72
Define, ‘Hydrophobic’?
Repeals water/is not water soluble
73
Define, ‘Hydrophilic’?
Attracted to water/is water soluble
74
Describe, the ‘Cleaning action of Soaps’?
Agitation causes ball like structures to form where the hydrophobic tail of the soap will dissolve in the oil/grease, the hydrophilic head will dissolve in the water, its negative charge will repel keeping the oil/grease suspended in the water which causes an emulsion of oil droplets in the water and the grease is removed
75
Define, ‘Emulsion’?
Emulsions are formed when small droplets of one liquid are suspended within another liquid
76
Define, ‘Hard water’?
Water that contains high levels of dissolved metal ions
77
What happens when Soap is used in Hard water?
An insoluble precipitate, scum is formed
78
What happens when Soapless Detergent is used in Hard water?
No scum is formed
79
Explain why Scum isn’t formed when you use Soapless detergents in Hard water?
The Soapless detergents do not react with Calcium and Magnesium ions
80
Explain why an ‘Emulsifier’ is used in an Emulsion?
To prevent non polar and polar molecules from separating into layers
81
Explain how ‘Emulsifier’ are formed?
A reaction between edible oils with glycerol
82
Explain how emulsifiers prevent non polar and polar liquids from separating?
The hydrophobic fatty acid chains dissolve in the non-polar liquid, the hydroxyl groups dissolve in the polar liquid, forming a stable emulsion
83
Why are Amino Acids call ‘Amino Acids’?
They contain the Amino acid group, -NH2 and a Carboxyl group, -COOH
84
What link forms between two amino acids?
Peptide link
85
What does an Pepide link look like?
-CONH-
86
Define, ‘Essential Amino Acids’?
Amino acids that have to be taken through our diets
87
Explain how ‘Proteins’ are formed from Amino acids?
A condensation reaction between amino acids
88
How are Proteins broken down?
A hydrolysis reaction
89
Define, ‘Denaturing’?
When Protein change shape and in food with protein when heated the texture changes
90
Explain why Proteins in food change the texture when heated?
They become denatured, they change shape, and the intermolecular bonds are broken
91
How can flavour be lost?
Overcooking or boiling polar/water soluble foods in water or cooking non polar/oil soluble foods in oil
92
What Oxidising Agent(s) can be used to distinguish ‘Primary Alcohols’, 'Secondary Alcohols', and 'Tertiary Alcohols'?
Acidified Potassium Permanganate, Acidified Sodium Dichromate, and Hot copper (II) oxide
93
What colour change occurs between an Alcohol and ‘Acidified Potassium Permanganate solution’?
Purple to Colourless
94
What colour change occurs between an Alcohol and ‘Acidified Sodium Dichromate solution’?
Orange to Green
95
What colour change occurs between an Alcohol and ‘Hot Copper (II) Oxide’?
Black to a brown solid being formed
96
What the Key sources of flavour?
Esters, Aldehyde, and Ketones
97
Describe, the uses of ‘Essential Oils’?
Perfumes, Cosmetics, Cleaning products, and as Flavouring in food
98
What are the Key components in ‘Essential Oils’?
Terpenes
99
Explain how ‘Terpenes’ are formed?
The joining together of Isoprene units
100
What is the molecular formula for Isoprene?
C5H8
101
What's the systematic name of Isoprene units?
2-methylbuta-1,3-diene
102
What method could you use to extract Essential Oils from plants?
Steam distillation
103
Explain how ‘Steam Distillation’ extracts Essential Oils from plants?
Steam passes over plants and extracts the essential oils, the mixture evaporates and passes through into a condenser, then the essential oil vapour is chilled and collected
104
Explain how ‘UV Light’ can cause sunburns and age skin?
The UV Light breaks bonds present within the skin
105
What is formed when UV lights break down bonds within the skin?
Free Radicals
106
Define, ‘Free Radicals’?
Molecules that have unpaired electrons and this results in them being extremely reactive
107
Explain the steps of Free Radicals forming stable molecules?
1. Initiation - UV Light will break bonds in a molecule
2. Propagation - Free radicals collide with other species, but the number of free radicals is kept the same
3. Termination - Free radicals collide with each other to form stable molecules
108
Define, ‘Free Radical Scavengers’?
Molecules which can react with free radicals to form stable molecules and prevent further reactions by donating electrons
109
Define, 'Neutralisation'?
When an acid and a base react to form water and a salt
