Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

HIGHER CHEMISTRY > UNIT 2 > Flashcards

UNIT 2 Flashcards

(100 cards)

Start Studying
1
Q

How are esters formed?

A

They are formed by reacting an alcohol with a carboxylic acid.

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

What is the formation of esters know as and why?

A

They are known as condensation reactions since the alcohol and carboxylic acid join together to eliminate water.

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

What kind of aromatic properties do esters have?

A

Esters have a pleasant,fruity smell.

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

what are esters used in?

A

Esters are often used in scented products such as deodorants and perfumes.

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

what are esters used in?

A

Esters are often used in scented products such as deodorants,perfumes and solvents.

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

What general properties do esters have?

A

Esters are able to dissolve a wide variety of compounds ans they ave relatively low boiling points which means they evaporate easily.

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

What general properties do esters have?

A

Esters are able to dissolve a wide variety of compounds and they have relatively low boiling points which means they evaporate easily.

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

What everyday products are esters found in?

A

They are found in everyday products such as nail varnish and spray paints.

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

What happens when esters dissolve in water?. What is this reaction known as?

A

When esters react with water they break down to from an alcohol and carboxylic acid. This reaction is known as ester hydrolysis.

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

What are fats and oils made up of?

A

They are made up of esters

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

How are fats and oils formed?

A

Fats and oils are formed from the reaction of glycerol and three fatty acid molecules

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

What is a triglyceride?

A

When glycerol and fatty acid molecules combine a triglyceride is produced. This is an ester which is either a fat or an oil.

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

How are fats formed?

A

Fats are formed from saturated fatty acids

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

How are oils formed?

A

Oils are formed from unsaturated fatty acids.

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

Are saturated fats solid or liquid?

A

SOLID!

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

Why are fats able to pack closely together?

A

Fats are able to pack closely together because the high degree of saturation gives the fat molecules an even,regular structure.

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

Why are the attractions between fat molecules greater than the attractions between oil molecules?

A

The efficient packaging of fat molecules increases the number of van der waals attraction therefore making the attraction between fat molecules greater.

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

What happens when a fat molecule is heated? ( in terms of van der waals forces)

A

When fat is heated,the van der waals attractions are broken and the fat melts.

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

Why is it difficult for oils to pack together?

A

In oils,the double bonds cause the molecules to have an even,distorted structure which makes it difficult fro them to pack closely together.

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

Why do oils have a lower melting point than fats?

A

There are fewer wan der waals forces of attraction between the oil molecules. Therefore it takes less energy to break apart the oil molecules which results in a lower melting point.

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

why are fats an essential component of out diet?

A

Fats and oils are an essential component of our diet as their non polar structure allows them to dissolve a number of essential vitamins eg A and D

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

Give at least 4 examples of proteins,where they are found and their function.

A

Collagen-
Found in tendons,muscle and bones
Gives structural support

Keratin-
Found in hair,skin and nails
Gives structural support

Myosin-
Found in muscoles
Helps muscles contract

Insulin-
Found in pancreas
Hormones which helps control blood glucose levels.

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

What are enzymes a type of?

A

They are a type of protein

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

What are enzymes described as?

A

They are described as biological catalysts.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are proteins made up of?
Proteins are made up of amino acids
26
What do amino acids contain?
Amino acids contain an amine group ( -NH2) and a carboxyl group (-COOH)
27
What are terpenes?
Terpenes are natural organic compounds. They are components of a variety of fruit and floral flavours and aromas
28
What are terpenes used in?
They are used in perfumes,essential oils and medicines.
29
Give and example of a terpene and its use.
Lavender used to relieve tension
30
What happens when terpenes are oxidised?
Terpenes in plants can be oxidised to produce the compounds responsible fro the distinctive aroma of spices
31
What are terpenoids?
Terpenes containing oxygen or other functional groups are known as 'terpenoids'
32
Are terpenes saturated or unsaturated?
Terpenes are unsaturated compounds
33
What are terpens built up from?
All terpenes are built from units of isoprene.
34
What is mycrene?
This is a component of plants,including bay,ylang-ylang and thyme.
35
What types of heads do soaps have? and what are they soluble in?
Soaps have a ionic head which is water soluble.
36
What kind of tail does soaps have and what are they soluble in?
Soaps have a hydrocarbon tail which is soluble in oil and grease.
37
which part of the soap is hydrophobic and which part is hydrophilic?
The hydrocarbon tail does not dissolve in water, it is hydrophobic. The ionic head does dissolve in water, it is hydrophilic.
38
Describe how soap works
The soap molecules can dissolve in the grease causing it to be covered in negative charge. The negative charges repel resulting in the grease breaking up into globules which are attracted to water allowing them to be washed away when water is added.
39
What are detergents like?
Detergents are compounds with a soap like structure which allows them to remove greasy stains. They have a non polar tail, which is oil soluble, and a polar head which is water soluble. An example of a detergent molecule is dodecylbenzenesulfonate.
40
What is the difference between soap and detergent?
The main difference is the head. The head part of the detergent will always be soluble in water but the detergent head will be formed from a carboxylate ion.
41
What happens with soap and detergents when in regions of 'hard water'
When hard water is mixed with water, instead of forming a soapy lather, a precipitate is formed. This precipitate reduces the cleansing action of the soap and build up to leave scum around baths,sinks and shower heads. Detergents do not form precipitate as they do not contain the carboxylate ion. Detergents are very useful in hard water areas as an alternative to soap.
42
What is an emulsion?
A liquid that contains small droplets of another liquid,such as soapy grease particles mixed in water.
43
What is an emulsifier?
Helps bring two substances together.
44
Give an example of an emulsion.
Mayonnaise: The olive oil and the vinegar in the mayonnaise will not mix and two separate layers will form. It contains egg yolk. The lecithin found in egg yolk acts as an emulsifier as it contains a charged part(water soluble) and a large hydrocarbon tail ( non polar). The vinegar is attracted to the charged part of the lecithin while the olive oil is attracted to the hydrocarbon part of lecithin.
45
What are essential oils?
Essential oils are concentrated extracts of aroma compounds found in plants
46
What are the properties of essential oils?
They are usually volatile and insoluble in water can can be found in almost any part of the plant
47
Where are terpenes found?
Terpenes are found in essential oils.
48
What are terpenes based on?
terpenes are compounds based on isoprene
49
What is the formula for terpenes?
C5H8
50
What do terpenes contain?
Terpenes contain isoprene units joined together
51
What does the oxidation of terpenes produce? and can you give an example?
The oxidation of terpenes produces many of the compounds responsible for the aroma of spices derived from plants. For example peppermint oil contains the terpene menthol and its oxidation products,methone. An examination of the structures of menthone shows that the structural change is an example of a secondary alcahol(menthol) being oxidised to form a ketone.
52
What does sunlight contain?
Sunlight contains ultraviolet light which is very high energy light capable of breaking chemical bonds.
53
What are the advantages and disadvantages of to UV light exposure?
Exposing our skin to UV light is beneficial as it allows us to make vitamin D, but it also causes our skin to age. Too much UV exposure can cause sunburn.
54
What product has been introduced to help protect our skin from sunburn?
Sun screen has been introduced to protect our skin from the dama
55
What product has been introduced to help protect our skin from sunburn?
Sun screen has been introduced to protect our skin from the damaging effects of UV
56
What does sunscreen contain?
They contain compounds that filter the UV light so that less UV reaches the skin.
57
What does sunblock do?
Sunblock contains compounds that reflect UV light so that it does not reach the skin at all.
58
What does UV light do to covalent bonds?
It breaks covalent bonds leaving two atoms with unpaired electrons.
59
What are free radicals?
Unpaired electron species.
60
Describe the particular sequence of reactions shown by free radicals using chlorine as an example.
Initiation: UV light is shone on a mixture of methane and chlorine. There is enough energy to break the Cl-Cl bond to produce two Cl atoms. Propagation: The highly reactive chlorine radicals react with the methane molecules. . This produces methyl radicals which then react with chlorine molecules. Termination: Two free radicals combine to form stable molecules.
61
How are proteins formed?
Amino acid molecules react together to form a protein molecule.
62
How is an amide link formed?
When an amine group reacts with a carboxyl group.
63
What kind of reaction is formed when amino acids join together?
condensation reaction
64
What is amide link also known as?
Peptide link
65
What are essential amino acids?
Essential amino acids are the amino acids that the body cannot make and therefore has to be obtained from the diet.
66
What is hydrolysis?
When proteins eaten they are broken down by the process of digestion to form the amino acids that make up the protein.
67
What does the hydrogen bonding between the protein molecules allow the protein to do?
It allows the long protein strands to to curl into different shapes.
68
What does denature mean?
Heating an enzyme causes the breaking of the hydrogen bonds and therefore causes the enzyme to change shape.
69
What functional group do alcohols contain?
-OH
70
What are the three different types of alcohol?
Primary- OH group joined to the end of the carbon chain. Secondary- OH joined to an intermediate carbon atom. Tertiary- OH joined to an intermediate carbon atom which also has a branch attached.
71
What effect does adding an OH group do to the boiling point?
Adding hydroxyl groups has a big effect on the boiling pint as the molecules are held together by hydrogen bonding in the solid and liquid state. More energy must be supplied to overcome the hydrogen bonds which attract the molecules.
72
Which alcohols can undergo oxidation and which cannot?
primary and secondary alcohols can be oxidized. | Tertiary alcohols do not undergo oxidation readily.
73
What are suitable oxidizing agents?
Suitable oxidizing agents are acidified potassium dichromate and hot copper oxide.
74
When primary alcohols are oxidized they produce.... | When secondary alcohols are oxidized they produce...
Aldehydes | ketones
75
How do we name aldehydes and ketones?
Branched aldehydes and ketones are named by giving priority to the carbonyl functional group. There is not need to indicate a number for the functional group when naming an aldehyde as the carbonyl group is always at the end of the carbon chain. However when naming a ketone it is necessary to specify the number of the carbonyl group.
76
What are used to distinguish between aldehydes and ketones?
Oxidising agents
77
What are the three most common oxidizing agents?
Fehlings solution, tollens reagent and acidified potassium dichromate.
78
When aldehydes are oxidized they produce...
Carboxylic acids
79
We can use the oxygen to hydrogen ratio to show that:
Oxidation occurs when there is an increase in the oxygen to hydrogen ratio. Reduction occurs when there is a decrease in the oxygen to hydrogen ratio.
80
What happens when carboxylic acids undergo reduction?
Carboxylic acids goes to an aldehyde adnd tehn a primary alcahol.
81
What is produced when an acid and an alkali are react?
Salt and water are produced.
82
Why is vitamin C soluble in water?
The polar OH- groups in vitamin C hydrogen bond to water. Vitamin C will dissolve in cooking water.
83
Describe limonene in terms of its intermolcular forces and its cooking properties.
Limonene is a non-polar molecules responsible for the lemon flavour of lemons. When lemons are cooked in oil, which is non polar, the limonene molecules will dissolve in the oil.
84
What gives proteins its specific shape?
Protein molecules that contain NH and C=O groups bind to other protein molecules through hydrogen bonding which gives them a specific shape.
85
Denaturing is?....
The process by which a protein changes shape.
86
Polar molecules are most likely to dissolve in.... | Non polar molecules are most likely to dissolve in....
Water | Oil
87
When aldehydes are oxidized what do they do to the taste of the food?
When aldehydes are oxidized carboxylic acids are produce which causes food to become spoiled as the carboxylic acids produce give a very acidic taste.
88
What method is used to prevent oxidation?. Describe itl.
Addition of an antioxidant. For example ascorbic acid (vitamin C) is an antioxidant that undergoes oxidation itself and will save the food from becoming oxidized.
89
What method is used to prevent oxidation?. Describe it.
Addition of an antioxidant. For example ascorbic acid (vitamin C) is an antioxidant that undergoes oxidation itself and will save the food from becoming oxidized.
90
What has manufacturers done to prevent the oxidation of edible oils?
Food manufacturers often package edible oils into an atmosphere of nitrogen to minimize exposure to oxygen. Addition of antioxidant compounds helps to prevent the edible oils from going rancid through oxidation.
91
What are essential oils?
They are concentrated extracts of the aroma compounds found in plants.
92
Give some properties of essential oils?
They are usually volatile and are insoluble in water. | They can be found in almost any part of the plant.
93
What family of compounds are found in essential oils?
Terpenes
94
What are terpenes based on?
isoprene
95
what is the formula for terpene compounds
C5H8n where n is the number of terpene units joined together.
96
What does the oxidation of terpenes produce?
The oxidation of terpenes produces many of the compounds responsible for the aroma of spices derived from plants.
97
What is a substitution reaction?
One of the H atoms in the methane is substituted for a Cl atom.
98
What are free radical scavengers?
They form stable molecules to help stop the free radical chain reactions that cause the skin to form wrinkles.
99
Give examples of free radical scavengers.
Vitamin C and E.
100
What are free radical scavengers added to and why?
They are added to foo,plastics and cosmetic products such as skin creams.

HIGHER CHEMISTRY (3 decks)

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