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General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
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SCIENCE
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Paper 5124/01
Multiple Choice
Question
Number
Key
Question
Number
Key
1
2
3
4
5
C
D
D
B
D
21
22
23
24
25
D
C
C
A
A
6
7
8
9
10
B
B
B
A
A
26
27
28
29
30
A
B
A
C
D
11
12
13
14
15
C
C
C
D
B
31
32
33
34
35
D
D
B
B
A
16
17
18
19
20
B
C
A
A
D
36
37
38
39
40
B
C
B
B
B
General Comments
Candidates found Questions 1, 3 and 14 to be straightforward, with Questions 2, 5, 7 and 9 also producing
a correct response from a significant number of candidates. Some more able candidates had difficulty with
Questions 13 and 16. Other questions, for example Questions 10, 15 and 19 discriminated well between
the more and less able candidates.
Comments on Specific Questions
Question 1
A small number of more able candidates incorrectly chose option D.
Question 2
This was well answered and showed very good discrimination with option A the favoured choice of weaker
candidates.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
Question 3
Candidates found this to be very easy with option B claiming the majority of the incorrect responses.
Question 4
This was well known and showed very good discrimination with less able candidates incorrectly choosing
option A.
Question 8
This question discriminated well with less able candidates of the opinion that ‘contains mercury’ is the
property essential to a clinical thermometer, option A. A number of the more able candidates incorrectly
chose option C.
Question 9
This was well known. Option B was the most popular incorrect response.
Question 10 and 11
These questions both showed very good discrimination with option B the most popular incorrect choice by
less able candidates in Question 10 and in Question 11 it was option A.
Question 13
The speed of sound in an unfamiliar unit, cm/s, found stronger candidates equally divided between the key,
option C, and, having ignored the unit, option D. Most of the less able candidates opted for the more familiar
expression of option A.
Question 14
Option C was the most popular distractor.
Question 16
This question was not well understood. Option D attracted more responses from, mainly less able,
candidates than did option B, the key. Option C attracted a large number of the more able candidates.
Question 17
The hazards of using electricity in the home are still not appreciated by candidates, many of whom chose
options A and B.
Question 19
This question showed very good discrimination with option D the preferred choice of less able candidates.
Question 21
A large proportion of the candidates correctly identified the burette as the piece of apparatus; however, there
were equally large numbers of candidates who chose option B, the pipette.
Question 23
Atomic structure is well understood by many of the candidates. Many of the weaker candidates simply
added the mass number and the proton number together and chose option D.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
Question 25
The majority of the candidates recognised that X is an inert gas and does not bond with other atoms. A
majority of the candidates chose option D, the formation of an ionic compound rather than option A, where a
covalent bond is formed between atoms of the same element.
Question 27
There was evidence of guesswork amongst the candidates. Candidates are expected to know that reactions
involving bond breaking are endothermic.
Question 28
This question was well answered by the more able candidates. Many of the candidates chose option B,
which is half the total time for the reaction to be complete but not the time when half the volume of carbon
dioxide has been evolved because the reaction slows down as the calcium carbonate is used up.
Question 30
There was evidence of guesswork here, particularly amongst the weaker candidates but the more able
candidates knew that bromine is a liquid and displaces iodine from potassium iodide.
Question 31
Half the candidates chose option C, an ionic compound, which shows a regular pattern of the two different
atoms. Candidates should be able to recognise that an alloy is a regular arrangement of atoms with a
random pattern of a second atom.
Question 32
The determination of a reactivity series from experimental data proved difficult for even the stronger
candidates and there was evidence of guesswork by the weaker candidates. Many candidates thought that
X is the most reactive element and chose either option B or option C.
Question 34
The production of ammonia by the reaction between an ammonium salt and an alkali, sodium hydroxide, is
not known by the majority of the candidates.
Question 37
The more able candidates knew that cracking produces an unsaturated molecule, ethene but a large
proportion of the weaker candidates chose option A, ethane, a saturated molecule.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
SCIENCE
Paper 5124/02
Theory (Physics)
Key Message
Candidates are advised to read each question carefully to ensure that their answers address the
question being asked.
General Comments
Most candidates showed evidence of being well-prepared and performed well. There was the
usual range of ability and it was pleasing to see that there were good answers to all questions.
Calculations were well done by many, although calculations involving changing units proved
difficult for some. Descriptions of experiments were clear and concise. Some candidates,
however, described the wrong experiment or gave general accounts rather than answering the
specific question that was asked.
Comments on Specific Questions
Section A
Question 1
This question required candidates to read the graph. The scale of the graph proved to be a
problem although most were able to state the length of the unloaded spring as between 6.3 cm and
6.5 cm to gain credit.
Only the most able could quote the extension of the spring when a weight of 4.6 N was attached.
The majority gave the length of the spring rather than how far it has extended. The correct answer
was 3.2 cm although a tolerance of 0.1 cm was allowed.
The graph proved to be difficult for all but the most able. These knew that beyond the limit of
proportionality, the length rises rapidly with added weight. The most common mistake was to
simply extend the existing line.
Question 2
(a)
Most candidates were able to calculate the mass as 110 g and so gained full credit. A
small minority worked out the mass correctly but incorrectly quoted it as 110 kg and a
small number did not give any unit.
(b)
Most candidates knew that they needed to multiply mass by gravitational field strength to
find the weight and so gained credit. The majority did not convert the mass to kilograms
and so did not get full credit.
(c)
The majority of candidates gained credit for stating that the gravitational field strength on
Earth is greater than on the Moon and so gained full credit.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
Question 3
(a)
A majority of candidates knew the general shape of the graph. Only the most able used
the information in the question to determine the key points to be plotted. Credit was
available for a line from zero to 40 m/s at 8 seconds. Further credit was awarded for a
horizontal line at 40 m/s running for 11 seconds and a straight line returning to 0 m/s in 6
seconds.
(b)
Almost all candidates gained credit for knowing that they needed to use K.E. = ½ mv2. A
sizeable minority used the wrong speed and there were a few who did not square the
speed.
(c)
Only the most able succeeded in working out the deceleration as -6.66 m/s2 and then
used F = ma to calculate the force as 3333 N to gain full credit. Most candidates gained
some credit for quoting F = ma or for working out the deceleration. A sizeable minority
incorrectly multiplied the mass by speed, distance or time to arrive at their answer.
Question 4
Credit was allowed for using the principle of moments and further credit was gained by calculating
the moment as 180 Nm. Most gained credit for doing one or both of these but only the most able
went on to gain full credit by calculating the correct answer of 60 N. A common mistake was to
multiply 15 N by 9 cm to find the moment.
Question 5
(a)
Almost all candidates knew that they need to use P.E. = mgh and so gained some credit
but few went on to calculate the correct answer as 180 J. The vast majority did not
convert the distance from centimetres into metres.
(b)
This question proved to be difficult for nearly all candidates. Almost all knew that they
need to divide work done by time to find the power but most were unable to work out that
the girl took 2 seconds for each step-up. Had they done so, they would have calculated
the correct answer of 90 W.
Question 6
(a)
Almost all candidates realised that conduction is the key process and most of these
gained credit for stating that energy is passed from particle to particle as a result of
increased vibration.
(b)
Only the most able minority gained credit for stating that black surfaces are good emitters
of radiation. Most candidates erroneously tried to explain why can A lost heat more
quickly by discussing increased absorption of radiation. Only a small number referred to
the effect of the water in can A being at a higher temperature.
Question 7
(a)
Almost all candidates identified the thermometer as a thermocouple and so gained full
credit. A small number incorrectly claimed that it was an industrial thermometer or a
bimetallic thermometer.
(b)
Most candidates gained full credit for realising that a liquid-in-glass thermometer would
not survive being at a temperature of 500 °C.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
Question 8
(a)
Most candidates gained credit for stating that sound waves are longitudinal whilst
electromagnetic waves are transverse, that sound cannot travel in a vacuum or that the
speeds were different. This gained them the credit that was available.
(b)
(i)
Most candidates gave the correct speed of electromagnetic waves in a vacuum. A
sizeable minority quoted 300 m/s or gave large but random values.
(ii)
Most candidates were able to use v = fλ to calculate an answer of 200 000 Hz and
so gained full credit. Those candidates who had given the wrong speed in (i) but
had used that speed correctly in (ii) gained full credit.
Question 9
This question proved to be difficult for all but the most able.
(a)
Although almost all candidates knew that they needed to divide p.d. by current to find the
resistance, few were able to determine the correct current in R1. This is found by
subtracting 0.8 A from the current from the battery. Most candidates used either 2.4 A or
3.2 A as the current in R1. Whilst these candidates gained some credit for trying to use
the correct formula, only those candidates who used a current of 1.6 A to calculate the
resistance as 7.5 Ω gained full credit.
(b)
Most candidates realised that the power in R2 is found by multiplying the p.d. by the
current in R2. A majority realised the current is 0.8 A and so calculated the correct answer
of 9.6 W. The main mistake was to use the wrong current.
(c)
The most straightforward way of calculating the combined resistance is by dividing the
battery voltage by the current in the battery i.e. dividing 12 V by 2.4 A. Only a very small
number of candidates realised this and tried, with varying degrees of success, to find the
resistance of each resistor and use 1/R = 1/R1 + 1/R2. Those who were able to do this
and find the correct answer of 5 Ω are to be congratulated on their persistence.
Question 10
(a)
The majority gained credit for realising that the number of neutrons is found by subtracting
the proton number from the nucleon number. The correct answer, obtained by most
candidates, is 146.
(b)
A nucleon number stated as being 237 and a proton number as 93 gained full credit. The
most common incorrect answers were 243 and 99.
(c)
The definition of half-life was known by most candidates. However, some answers lacked
the precision needed to gain credit.
Section B
Question 11
(a)
Many candidates gained most of the available credit for describing a suitable experimental
arrangement and detailing the readings that need to be taken. Weaker candidates
described an experiment involving reflection using mirrors. Others simply drew a diagram
of a ray being refracted without describing an experiment.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
(b)
This proved to be extremely difficult with few candidates drawing a ray diagram that
allowed them to find the focal length. Most candidates drew the formation of a real image,
missing the reference in the question to the image being upright and virtual.
Question 12
(a)
This question was very popular. Most candidates described a method of stroking but their
answers often lacked the detail needed to gain full credit. A small number are under the
impression that it is necessary merely to hold the magnet close to a steel bar in order to
make a magnet.
(b)
Most candidates gained credit for describing an arrangement that had the magnet inside a
coil carrying alternating credit. A small number thought that the current needs to pass
through the magnet. Only the most able gained further credit by giving appropriate detail
such as the need to remove the magnet to a great distance or to reduce the current to 0.
(c)
Surprisingly few candidates gained credit for stating that an electromagnet consists of a
coil carrying direct current wrapped around a soft iron core. Even fewer candidates stated
that magnetism is induced in the iron and steel in the scrap yard in such a way that
opposite poles result in attraction. There were many descriptions of domains in the iron
and steel but rarely did these descriptions lead to the explanation that was asked for.
Candidates do not gain credit for answering a different question to that which is asked.
Question 13
(a)
The majority of candidates knew the names of the wires connected in a three-pin plug and
most gained credit for knowing the colour of the insulation around them. A minority
confused the colours around the live wire and the neutral wire whilst a similar minority
confused the live wire with the earth wire – a potentially fatal misunderstanding.
(b)
This question was well-answered. Most candidates identified the earth wire as the one
that did not carry current in normal use. Most also gained further credit by showing that
they knew the function of the earth wire although most were content to state that it
prevented electric shocks. It was pleasing to see that a number knew that the function
was to cause a large current to flow to earth, thus blowing the fuse and switching off the
current, if the live wire touched exposed metal parts of the appliance.
(c)
Most candidates calculated the current as 8 A but not all went on to give a convincing
reason why the 5 A fuse is unsuitable. Only the most able stated that the fuse would melt
whenever the kettle is switched on. Many stated that the fuse would not blow even if a
fault caused the current to be too high which, of course, gained no credit.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
SCIENCE
Paper 5124/03
Theory (Chemistry)
Key message
Candidates’ performance is enhanced by the ability to interpret information and solve problems.
General comments
The general quality of candidates' work appeared much improved on previous years. The ability to
handle information and solve problems was highly in evidence. Skill at writing balanced, chemical
equations, an important chemical ability, was often shown as was the ability to solve problem of a
chemical and mathematical nature.
Comments on Specific Questions
Section A
Question 1
Any of the many uses of these materials, in addition to those specified in the syllabus, were
accepted. The main responses were: aluminium – aircraft construction, having a low density;
calcium carbonate – soil treatment, reducing acidity, but not as a fertiliser; diamond –
drilling/cutting, having great hardness, though not strength, as commonly given; helium - filling
balloons, being lighter than air is the most important reason for using helium to fill (weather)
balloons but it is not used, of course, in filling hot-air balloons.
Question 2
This was variably answered, with some answers being excellent. As the question required
‘names’, correct chemical formulae were accepted but if this was the case, full credit could not be
achieved.
(a)
Either ‘carbon dioxide’ or ‘ethanol’ were accepted as the product of fermenting sugar.
(b)
Either ‘brass’ or an ‘alloy’ were the correct answers here. This was not well known.
(c)
‘Ammonia’ was accepted but neither ‘ammonium’ nor ‘NH4’ were awarded credit.
(d)
The name of the substance formed, i.e. silver chloride, was needed but ‘white precipitate’
was rejected.
(e)
‘A sodium ion’ results from removing an electron from a sodium atom. This was not well
known.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
Question 3
(a)
Either ‘filter funnel’ or ‘filter paper’ were accepted as pieces of apparatus used to separate
a precipitate from a solution.
(b)
‘Measuring cylinder’ was the correctly given answer. ‘Volumetric flask’, though only
occasionally given, was not accepted. ‘Pipette’ was not considered as an appropriate and
practicable choice.
(c)
‘Condenser’ was accepted with ‘Liebig condenser’, equally valid, being commonplace.
(d)
Few candidates chose a ‘burette’ to add 17.3 cm3 of solution to a flask. Evidently some
Centres use ‘graduated pipettes’ and this was accepted as a correct response.
Question 4
(a)
Partial credit was awarded where A was the most reactive metal and D the least reactive.
Further credit was available if candidates had positioned C and B correctly.
(b)
The deductions required here could best be based on a knowledge and recall of the
reactivity series listed in the examination syllabus. Many candidates sketched in rough on
the examination paper this reactivity series and were evidently using it as a basis for their
answer. However, when a candidate correctly chose a metal outside the series given in
the syllabus, the response was awarded full credit.
Question 5
In the first row, the name and formula was usually correctly given. In the second row, ‘methanoic
acid’ was often given, incorrectly, for ‘ethanoic acid’. ‘COOH’ written as such was sufficient to earn
the credit available for ‘characteristic group of atoms’.
Question 6
(a)
The correct name and formula for an acid was often written correctly but not so those of
an alkali.
(b)
While the name of a particular salt and water were expected to be answered as the
product of the reaction of a named acid and a named alkali, ‘salt and water’ were also,
perhaps generously, accepted. This was well answered.
(c)
While some candidates knew that hydrogen ions in excess are the cause of acidity, very
few knew that alkalinity is caused by an excess of hydroxyl ions.
Question 7
(a)
That this atom has seventeen protons and eighteen neutrons in its nucleus was well
determined.
(b)
Candidates did not find the general nature of this question easy. Explanations needed
candidates to apply their knowledge of electrovalent and covalent bonding to a chlorine
atom when donating or sharing an electron.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
Question 8
Candidates were not expected to have any experience of this mineral, its chemical formula being
given in the question thus testing their problem solving rather than factual recall skills.
(a)
(i)
Most candidates could correctly calculate the relative molecular mass of vanadanite.
(ii)
Few candidates realised that as three vanadium atoms are present in vanadanite’s
molecule, all should be included in the determination of its percentage by mass.
(i)
This was not an easy chemical equation to balance but many candidates were
successful in doing so.
(ii)
Most candidates realised that to calculate the mass of magnesium needed to
produce 5 kg of vanadium the chemical equation, previously balanced, needed to be
used. If the candidate had not been successful in balancing the equation in (i) yet
had used it correctly here, credit was awarded. In other words, candidates were not
penalised twice for making a single error.
(b)
Section B
Question 9
(a)
(b)
(i)
The substances E, F, G and H were, respectively, copper(II) nitrate, ammonia,
ammonium hydroxide, and copper(II) hydroxide. Identification and not naming was
required and so chemical formulae were accepted, but only when the completely
correct chemical formula was used. This was very well answered.
(ii)
Most candidates decided to give the chemical equation for the reaction between
sodium hydroxide and copper(II) sulfate, though other, perhaps simpler, equations
were equally acceptable. Many correctly balanced equations were given.
To gain full marks in describing a means of forming crystals from a dilute solution
candidates needed to include any four of the following in logical order: boil to concentrate,
leave to crystallise/cool, separate/filter, wash with distilled water, dry with filter/blotting
paper. Many candidates gained full marks.
Question 10
(a)
A simple description of ‘cracking’ was expected but many candidates described ‘fractional
distillation’ and hence received no credit for this section. The description should have
included any four of ‘cracking’, ‘heat (or a specific temperature e.g. 600 oC ± 50 oC)’,
‘catalyst’, ‘name of catalyst (any one of aluminium oxide, silicon(IV) oxide, porous pot,
zeolite – at 500 oC) and ‘finely divided’.
(b)
Using bromine to distinguish between ethene and ethane was well known and correctly
described. ‘Going clear’ was not accepted as a correct description of ‘turning colourless’.
(c)
This problem was often attempted via ‘mass of oxygen formed’, and while this will
ultimately supply a correct answer there are so many stages that an arithmetical slip can,
and often did, take place. The application of Avogadro’s Principle is much simpler and an
answer then comes quickly by direct application of the chemical equation.
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© 2011
General Certificate of Education Ordinary Level
5124 Science November 2011
Principal Examiner Report for Teachers
Question 11
There were many excellent answers here.
(a)
Lithium and sodium were usually identified correctly by using the proton numbers and the
Periodic Table of Elements supplied in the question paper.
(b)
Candidates had little difficulty in writing the electronic structures of these two elements
and realised that the group of the Periodic Table in which they are placed depends upon
the number of electrons in their outer shells.
(c)
These three elements show many of the physical and chemical properties of metals and
all were acceptable including electrical and thermal conductivity. High reactivity earned
no marks. Trends in properties were not as well known. The most common error was to
believe that the trend moving from lithium to potassium in melting/boiling points is to
become higher rather than lower. Many gave the correct trend in chemical reactivity.
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© 2011