HIGHER CHEMISTRY
Cooking and Oxidation of Food Past Papers
Lesmahagow High School
Higher Chemistry
Cooking and Oxidation of Food - Past Paper Homework
Questions
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HIGHER CHEMISTRY
Cooking and Oxidation of Food Past Papers
Part 1 consists of 10 multiple choice marks.
1
Which of the following is an isomer of hexan-2-ol?
2
Aspirin and oil of wintergreen are used in medicine. Their structures are shown
below.
Identify the term which can be applied to aspirin but not to oil of wintergreen.
A
Aldehyde
B
Ketone
C
Ester
D
Carboxylic acid
2
1
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HIGHER CHEMISTRY
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Cooking and Oxidation of Food Past Papers
Apples and bananas turn brown when cut or bruised. The first step of the reaction
causing the browning is shown below.
1
Which of the following terms correctly describes this reaction?
A
Reduction
B
Oxidation
C
Dehydration
D
Condensation
4
Which of the following structural formulae represents a tertiary alcohol?
3
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HIGHER CHEMISTRY
Cooking and Oxidation of Food Past Papers
5
Which line in the table shows the correct functional group for each homologous
series?
1
6
Which alcohol could be oxidised to a carboxylic acid?
4
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HIGHER CHEMISTRY
7
When a protein is denatured
A
B
C
D
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Cooking and Oxidation of Food Past Papers
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its overall shape is distorted
its amide links are hydrolysed
it is broken into separate peptide fragments
it decomposes into amino acids.
A compound with molecular formula C6H12O2, could be
A
B
C
D
1
hexanal
hexan-2-ol
hexan-2-one
hexanoic acid.
9
Erythrose can be used in the production of a chewing gum that helps prevent tooth
decay.
Which of the following compounds will be the best solvent for erythrose?
5
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HIGHER CHEMISTRY
Cooking and Oxidation of Food Past Papers
10
Which two isomers would each produce an acid when warmed with acidified
potassium dichromate solution?
A
B
C
D
1 and 2
2 and 3
1 and 4
3 and 4
6
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HIGHER CHEMISTRY
Cooking and Oxidation of Food Past Papers
Part 2 consists of 20 extended answer marks.
11
Butanone is an important solvent. Butan-2-ol is required for its production.
(a) Name the type of reaction that takes place when butan-2-ol is converted into
butanone.
1
12
Genetically modified bacteria can produce 2-methylpropan-1-ol by fermentation.
(a) Draw a structural formula for 2-methylpropan-1-ol.
1
13
Two typical compounds present in many perfumes are shown.
(a) Why does geraniol evaporate more slowly than limonene?
1
(b) The structure of one of the first synthetic scents used in perfume is shown below.
Name the family of carbonyl compounds to which this scent belongs.
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HIGHER CHEMISTRY
Cooking and Oxidation of Food Past Papers
14
Traces of a liquid were discoverd in a bottle believed to contain perfume
belonging to Queen Hatshepsut, a ruler of Egypt over 3500 years ago.
Perfumes were made by dissolving plant extracts containing pleasant terpenes
and esters in an edible oil. A little ethanol and water may also have been
added.
Using your knowledge of chemistry comment on the possible smell(s) when
such a bottle is opened after being stored for thousands of years.
3
15
The element boron forms many useful compounds.
(a) Borane (BH3) is used to synthesise alcohols from alkenes.
The reaction occurs in two stages.
(i)
Name the alcohol produced in stage 2.
1
(ii)
Draw a structural formula for the alcohol which would be formed from
the alkene shown below.
1
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HIGHER CHEMISTRY
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Cooking and Oxidation of Food Past Papers
A student wanted to measure the volume of oxygen gas given off over a five minute
period, when samples of potato were added to a solution of hydrogen peroxide.
(a) Complete the diagram below to show how the volume of oxygen gas given off
could be measured.
1
(b) The student wanted to be able to repeat the experiment at various temperatures
between 20oC and 70oC to investigate the effect of temperature on the protein
catalysing the reaction.
(i)
What is the most appropriate way of heating the side-arm test tube to
control the temperature accurately over this range?
1
(ii)
At 70oC the protein structure changes so that it no longer works as a
catalyst.
What change happens to the structure of all proteins when they are heated?
1
(iii)
Suggest a factor which should be kept constant during the experiment. 1
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HIGHER CHEMISTRY
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Cooking and Oxidation of Food Past Papers
5-butyl-4-methyltetrahydrofuran-2-ol is a flavour compound found in whisky stored
in oak barrels
Write the systematic name for the compound shown below
18
1
Chocolate contains various compounds.
(a)
Many of the flavour and aroma molecules are aldehydes and ketones. Two
examples are shown below.
Phenylethanal can be easily oxidised but 1,3-diphenylpropan-2-one cannot.
(i)
(ii)
Name a chemical that could be used to distinguish between these two
compounds
1
Name the type of organic compound formed when phenylethanal is oxidised.
1
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HIGHER CHEMISTRY
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Cooking and Oxidation of Food Past Papers
Glycerol monostearate is an emulsifier used in chocolate.
(a) Why is glycerol monostearate added to chocolate?
1
(b) Draw a structural formula for glycerol.
20
1
An antioxidant used in skincare is vitamin C, C6H8O0.
Copy and complete the ion-electron equation for the oxidation of vitamin C.
1
21
Alcohols are widely used in antifreeze and de-icers.
Why is the boiling point of ethane-1,2-diol much higher than the boiling point
of propan-1-ol?
1
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HIGHER CHEMISTRY
Cooking and Oxidation of Food Past Papers
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