DCHS Science Dept
Higher Chemistry
Unit 2
The World of Carbon
Homework Booklet
Homework 2.1
1. Naphtha fractions from a distillation column contain a mixture of many
hydrocarbons with low octane ratings. To improve its qualities as a petrol
(i.e. increase its octane rating) the naphtha is passed over a catalyst of
aluminium oxide coated with platinum.
The three reactions shown below are typical of this process.
H
H
H
H
H
H
H
C
C
C
C
C
C
H
H
H
H
H
H
H
a) What is the name given to this type of process?
b) Name the three compounds formed.
…………………………………………………
1
………………………………………………………………………….
…………………………………………………………………………………………………………………………………………………..
3
c) Why are the products better fuel molecules for a car engine?…………………………………
………………………………………………………………………………………………………………………………………………….
1
2. Explain why the following compounds may be added to petrol.
a) Tetraethyllead (C2H5) 4Pb. ………………………………………………………………………………………….
……………………………………………………………………………………………………………………………………………
1
b) butane and pentane. ……………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………………….
3.
1
a) Describe the advantages of using the following as alternatives to petrol.
i) ethanol.
…………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………………….
1
ii) hydrogen. …………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………………….
iii) methanol. …………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………………….
1
b) For methanol, describe two disadvantages in its use as a motor vehicle
fuel. ……………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………..
4.
1
Hydrogen and ethanol are both being put forward as alternatives to petrol
Describe the process used to produce
a) ethanol.
…………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………….
1
b) hydrogen. …………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………….
1
5. Draw the extended structural formulae for all 5 isomers of hexane.
b) Name all 5 isomers using systematic nomenclature.
5
7. Draw the extended structural formula for
a) 2,4-dimethylheptane.
b) 3-ethyl-2-methylpentane.
c) 3-methylbut-1-yne.
3
Total = 20 marks
Homework 2.2
1. Write the systematic names for
H
a)
H
H
H
C
C
H
H
H
C
C
H
H
b)
H
H
H
C
C
C
C
H
H
H
C
H
H
CH2
CH3
C
CH2
CH
CH2
CH3
CH3
CH3
H
H
CH2
CH3
H
…………………………………………………………………….
……………………………………………………………………
2
2. Write the structural formulae and names of 3 isomers of pentene.
3. Identify the homologous series each of the following molecules belongs to
and name the functional group present.
H
a)
H
H
O
3
b)
CH3
H
C
C
C
H
H
H
C
H
CH2
CH3
O
………………………………………………………………………………….
………….………………………………………………………………….
c)
d)
H
H
H
C
C
H
H
H
N
H
H
H
C
C
H
H
H
C
O
H
H
…………………………………………………………………………..……
e)
O
H
C
…………..…………………………………………………………………
f)
CH3CHCHCH3
O
…………………………………………………………………………..……
…………..……………………………………………………………… 6
4. Using the simplified symbol for a benzene ring draw the structural formulae for
a) Methylbenzene (toluene).
b) Benzoic acid
2
5. Draw the full structural formulae for each of the following compounds.
a) Butan-2-ol
b) Pentanal
c) Ethanoic acid
3
6. Give the systematic names for the following compounds.
a)
b)
OH
O
c)
C
CH3
CH
CH3
CH2
CH3
CH
CH3
CH2
CH3
CH
CH3
……………………………………………………
……………………………………………..
………………………………………..
3
7. Give the molecular formula for the compound shown below.
CH3
CH3
…………………………………………………………………..
1
Total = 20 marks
Homework 2.3
1. The dehydration of butan-2-ol can form two different isomers of butene.
a) Draw a diagram of the apparatus you could use in the laboratory to bring
about the dehydration of butan-2-ol. Name any chemicals used.
2
b) What is meant by the term ‘dehydration’?
…………………………………………………………………….
1
c) Draw and name the structures of the two butene isomers formed.
…………………………………………………………………
…………………………………………………………………….
4
d) An isomer of butan-2-ol gives only one product on dehydration. Name this
isomer.
………………………………………………………………………………………………………………………………………..
1
2. Draw the structural formulae for each of the following alcohols and state
whether the alcohol is a primary, secondary or tertiary alcohol.
a) Pentan-3-ol.
b) 2-methylbutan-1-ol
c) 3-ethylpentan-3-ol.
……………………………………
………………………………………….
……………………………………
3.
A
B
CH3CH2OH
D
C
CH3CHOHCH3
E
CH3COCH3
CH3CH2COOH
F
CH3CH2CHO
CH3COOH
Which box, or boxes, show(s) a substance which
a) can be oxidised to an alkanal (aldehyde)?
……………………………………………………………………
b) is an alkanone (ketone)?
……………………………………………………………………
c) is an alkanoic (carboxylic) acid?
…………………………………………………………………….
d) is a primary alcohol?
…………………………………………………………………….
e) can be formed by the oxidation of B?
……………………………………………………………………
5
4. The alcohol, propan-1-ol, can be oxidised by passing the alcohol vapour over hot
copper(II) oxide.
a) Draw a labelled diagram of the apparatus that would be used to carry out this
experiment in the laboratory.
2
b) Oxidation of propan-1-ol yields a compound X, formula C3H6O, which
can be further oxidised to compound Y, formula C3H6O2.
i) Name and draw the structure of compound X.
……………………………………………………
2
……………………………………………………
2
ii) Name and draw the structure of compound Y.
c) Name two other oxidising agents which could be used to carry out the oxidation.
…………………………………………………………………………………………………………………………………………………………
2
d) If propan-2-ol was used in place of propan-1-ol there would be only one
oxidation product. Name and draw the structure of this product.
…………………………………………………..
2
Total = 26 marks
Homework 2.4
1.
Two compounds A and B, both having the formula C4H8O were mixed with
Fehling’s solution and the the mixture warmed in a water bath. Only
compound B gave an orange-red precipitate.
a) Name compounds A and B.
A ……………………………………………………………..
B ……………………………………………………………..
2
b) Draw the extended structural formulae of A and B.
A
B
2
c) Name another reagent which could also be used to show the difference
between compound A and B and say what would happen when this reagent
is reacted with A and B.
…………………………………………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………………………….
2
2. On diagrams below and then circle and name the following groups:a) hydroxyl groups.
b) carboxyl groups.
c) ester linkages.
CH3
O
CH3
O
C
O
C
O
O
OH
C
OH
3
3. a) Name and draw the structural formula of the ester formed between
i) propanol and butanoic acid.
ii)
………………………………………………………….
2
………………………………………………………….
2
C4H9OH and CH3CH2COOH
4. Name the alcohol and acid used to form the following esters.
a)
b)
CH3CH2CH2COOCCH3
………….……………………………………………………………………………………… 1
O
C
O
CH3
……………………………………………………………………………………………….
1
CH3
5. A pupil made the ester ethyl propanoate in a test tube and poured the reaction
mixture into a beaker containing sodium hydrogen-carbonate solution.
a) Name the acid and alcohol used to make the ester.
…………………………………………………………………………………………………………………………………………………………
2
b) What two things would the pupil observe when the ester is poured into the
sodium hydrogen-carbonate solution?
…………………………………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………………………………
2
c) The pupil heated the reaction mixture using a hot water bath. Why was the
reaction mixture not heated directly with a Bunsen flame?
…………………………………………………………………………………………………………………………………………………………
1
d) What other chemical would be added to the reaction mixture in order to
increase the yield of ester formed.
………………………………………………………………………………………………………………………………………………….……..
Total = 21 marks
1
Homework 2.5
1. Dichlorodifluoromethane (CF2Cl2) belongs to a group of compounds called
chlorofluorocarbons (CFCs).
a) Give two uses of CFCs…………………………………………………………………………………………………………….…
………………………………………………………………………………………………………………………………………………………. 2
b) The use of CFCs was phased out as a result of the 1987 Montreal
Convention. Explain why the convention came to decide that this was necessary.
………………………………………………………………………………………………………………………………………………………. 1
2. Ethene is used in vast quantities each year for the making of addition polymers.
Give two different sources of ethene and name the type of reaction in each case.
……………………………………………………………………………………………………………………………………………………….
……………………………………………………………………………………………………………………………………………………….
3.
A
B
ethene
D
C
propene
E
toluene
G
benzene
F
chlorobutane
H
propane
3
ethane
I
cyclopropane
1,2-dichloroethene.
Which box, or boxes, show(s) a substance which:a) is an alkane.
…………………………………………..
b) is made by reacting butene with hydrogen chloride.
…………………………………………..
c) has the molecular formula C3H6
…………………………………………..
d) is used to make polythene.
…………………………………………..
e) is converted to propene by cracking.
…………………………………………..
f) is made by reacting ethyne with chlorine.
…………………………………………..
g) is aromatic.
…………………………………………..
7
4. A polyamide is a polymer that can be made by reacting a diacid with with a diamine.
a) Draw the functional group present in a diacid.
1
b) Draw the functional group present in a diamine.
1
c) Using two molecules of the diacid and two molecules of the diamine shown
below show how part of a polyamide polymer can be formed.
O
C
O
H
H
H
C
C
H
H
O
H
N
C
H
O
H
H
H
H
C
C
C
C
H
H
H
H
H
N
H
H
d) Explain why this type of reaction is called a condensation polymerisation.
…………………………………………………………………………………………………………………………………………………….
1
e) Draw the amide link which is formed when a polyamide is formed.
1
f) What would you replace the diamine with in order to form a polyester?
………………………………………………………………………………………………………………………………………………………….
Total = 18 marks
1
Homework 2.6
1. a) Show using two molecules of the diacid and two molecules of the diol how
a polyester molecule can be formed using the molecules shown below.
H
H
O
H
H
C
C
H
H
H
O
O
H
O
C
O
C
O
2
b) In your drawing of the polymer circle and name the
i) ester linkage
ii) benzene ring.
2
c) What change in structure would the diol have if it was to be used to form
a polyester resin?
............................................................................................................................................................
1
d) What difference in structure exists between a polyester fibre and a polyester
resin?
............................................................................................................................................................
1
2. a) Draw a diagram to show how urea [CO(NH2) 2] and methanal [CH2O] can react
together to form a thermosetting polymer.
2
b) What is meant by the term ‘thermosetting’?
....................................................................................................................................................
1
c) Explain why the polymer formed between urea and methanal is thermosetting.
....................................................................................................................................................
1
d) What type of polymerisation process occurs when urea and methanal react?
....................................................................................................................................................
1
3. Write a brief note on each of the following polymers, stating their unusual properties.
a) Kevlar.
...........................................................................................................................................
b) Biopol.
...........................................................................................................................................
c) Poly(ethenol) ....................................................................................................................................
d) Poly (vinly carbazole) ......................................................................................................................
4
4. Bucrylate is an ester which is used in surgery for repairing torn tissue.
H
H
CN
H
C
C
H
H
C
O
O
H
C
H
H
C
C
C
H
H
H
H
It instantaneously polymerises when it come in contact with ionic solutions.
a) What tyoe of polymerisation (addition or condensation) will bucrylate undergo?
....................................................................................................................................................
1
b) Draw the structure of part of the polymer formed showing three monomer units
linked.
1
c) Draw the structure of the repeating unit in the polymer molecule.
1
Total = 18 marks
Homework 2.7
1. Explain, in terms of structure, why fats are solids and oils are liquids at room temperature.
............................................................................................................................................................................
............................................................................................................................................................................
............................................................................................................................................................................
............................................................................................................................................................................
.......................................................................................................................................................................... 2
2. a) Draw the extended structural formula for a molecule of glycerol.
1
b) What is the systematic name for a molecule of glycerol.
............................................................................................................................................................
1
c) Explain why fats are sometimes referred to as triglycerides. ...................................
.....................................................................................................................................................
1
c) What do you understand by the term ‘fatty acid’?
...........................................................................................................................................................
1
3. The hydrolysis of a fat produces glycerol and fatty acids.
a) What does the term hydrolysis mean? .................................................................................
..................................................................................................................................................
1
b) State the ratio of glycerol molecules to fatty acid molecules.
..................................................................................................................................................
1
c) A triglyceride produces only glycerol and palmitic acid, CH3(CH2)14COOH, on hydrolysis.
i) Draw the structural formula for the triglyceride.
1
ii)Explain whether the triglyceride is likely to be a fat or an oil. ...................................
..................................................................................................................................................
1
4. The structure of an oil can be represented by
H H
-C=C–
H H
C=C–
H H
-C = C -
a) Draw the structure of the fat which would be produced by ‘hardening’ this oil.
1
b) What is the effect of hardening on the melting point of this oil?
..................................................................................................................................................
1
c) Name the kind of chemical reaction that is taking place during this hardening
process. ........................................................................................................................................
1
5. Soap can be produced by the reaction of fats and oils with sodium hydroxide solution.
a) Name the kind of reaction that is taking place. ................................................................
1
b) Describe the structure of soap ...........................................................................................
.......................................................................................................................................................
2
6. Biodiesel is a mixture of esters which can be made by heating rapeseed oil with
methanol in the presence of a catalyst.
O
C21H39 – C – O CH2
O
C21H39 – C –O- CH
O
+ 3CH3OH -->
3 C21H39 – C – O CH3 + X
O
C21H39 – C – O CH2
a triglyceride in
rapeseed oil
a) Name compound X.
methanol
a component of
biodiesel
........................................................................................
1
b) A typical diesel molecule obtained from crude oil has the molecular formula C16H34
(hexadecane). Other than the ester group, name a functional group present in biodiesel
which is not present in hexadecane.
....................................................................................... 1l
Total = 18 marks
Homework 2.8
1. The following is part of a protein molecule (the bond angles are not correctly
shown).
H CH3
CH3
–N–CH–C–N–CH2–C–N–CH–C–N–CH2–C–
OH
OH
OH
a) Draw the extended structural formula of two amino acids obtained on
hydrolysis of this protein.
2
1
b) On diagram above and circle the amide links.
2.
A
B
C
CH2
NO2–CH2–COOH
NH2–CH(CH3)–COOH
CH3
O
C
CH2
OH
O
D
E
NH2–(CH2) 6–NH2
NH2–CH2–C
H
O
F
O
HO
C–CH2–NH2
Which box(es) contain:a) an amino acid?
.............................................................................................................................
b) an ester?
.............................................................................................................................
c) a molecule capable of carrying out a condensation reaction at both ends of the
molecule?
.............................................................................................................................
3. What is meant by the term ‘essential amino acid’?
3
...........................................................
..............................................................................................................................................................
1
4. What is meant by
a) fibrous and globular proteins.
.....................................................................................................
................................................................................................................................................................. 2
b) enzyme denaturing...............................................................................................................................
................................................................................................................................................................. 1
5. Examine the graphs below.
Rate o f
hy dr olysis
of a
pr otein
A
B
C
10
30
20
40
50
T emp er atur e /
°C
a) Which graph is likely to represent the results from a series of reactions using an enzyme?
Explain your answer. .............................................................................................................................
.................................................................................................................................................................
................................................................................................................................................................. 2
b) To which family of compounds do enzymes belong?
.............................................................
1
c) Name the four elements which must be present in all enzyme molecules.
................................................................................................................................................................. 1
6. Glycine is an amino acid with the following structure.
N
H
O
H
H
C
H
C
O
H
a) What is the systematic name for this molecule? ..................................................................
1
b) Draw the structure of part of the polymer chain that would be formed when three glycine
molecules polymerise.
c) What type of polymerisation process is taking place? ...........................................................
1
1
Total = 17 marks
Homework 2.9
1. In theory, one mole of benzene, C6H6, can be converted into 1 mole of
methylbenzene, C6H5CH3.
In an experiment 0.1 mole of benzene produced 4.6 g of methylbenzene.
Calculate the percentage yield for the conversion of benzene to methylbenzene.
3
2. CH OH + C H COOH
3
2 5
methanol
C2H5COOCH3 + H2O
ethanoic acid
methylethanoate
In an experiment, 20.2g of methylpropanoate is obtained from 9.65g of methanol.
Calculate the percentage yield.
3
3. In an experiment 3.9g of propan-1-ol was oxidised to propanal.
C3H7OH
oxidation
C2H5CHO
Given that the percentage yield was 65%, calculate the mass of propanal formed.
3
4.
H
H
C
H
H
C
H
+
Br
Br
C
Br
H
H
H
C
C
C
H
H
Br
H
H
a) Write a word equation for this reaction.
...................................................................................................................................................................
b) What kind of reaction is taking place? ......................................................................................
1
1
c) In an experiment 2.6g of the alkene produced 10.2g of the product.
Calculate the percentage yield.
3
5. When 6.2 g of copper(II) carbonate was decomposed by heating, 3.8 g of
copper(II) oxide was formed.
a) Write a balanced chemical equation for the reaction.
...................................................................................................................................................................
1
b) Calculate the percentage yield of copper(II) oxide.
3
6.
N2(g) + 3H2(g)
2NH3(g)
Under test conditions, 4 kg of hydrogen reacts with excess nitrogen to produce 20kg
of ammonia.
a) What name is given to this process?
...................................................................
1
b) Calculate the percentage yield of ammonia.
3
Total = 22 marks