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COMBINED SCIENCE B

OCR 2024
GCSE Combined Science B Twenty First Century Science
J260/06: Chemistry (Higher Tier)

with Marking Scheme Merged
...
Do not write in the barcodes
...
You can use an HB pencil, but only for graphs and diagrams
...
If you need extra space use the
lined pages at the end of this booklet
...

• Answer all the questions
...
Marks might
be given for using a correct method, even if your answer is wrong
...

• The marks for each question are shown in brackets [ ]
...

• This document has 24 pages
...


2
1
(a) Table 1
...

Table 1
...
54 × 10

Fullerene molecule

–9
1
...
88 × 10

Platinum nanoparticle

–8
1
...
and
...

Smallest
...


...

[2]
(b) Nanoparticles make effective catalysts because they have a high surface area to volume ratio
...
2 shows the surface area to volume ratio of some different sized particles
...
2
Nanoparticle
Size of Particle (nm)

Particle of
Fine Powder

Particle of
Coarse Powder

60

600

6000

0
...
01

0
...


...


...
[2]
© OCR 2024

3
(c) The nanoparticle shown is a cube
...
h

l

w

NOT TO SCALE
Calculate the surface area of the nanoparticle
...
nm
[3]

© OCR 2024

Turn over

4
2

A student is investigating the reaction between calcium hydroxide and hydrochloric acid
...

3
1 g masses of solid calcium hydroxide are added one by one to 50 cm of dilute hydrochloric
acid in a plastic cup
...

1
...

2
...

[2]
(b) The table shows the student’s results:
Mass of calcium hydroxide (g)

Temperature of hydrochloric acid (°C)

0

22
...
5

2

37
...
5

4

52
...
5

Plot the results from the table on the graph
...


(c) Draw a line of best fit
...

y = mx

y = mx

2

y = mx + c

y = mx – c

[1]

(e) Calculate the change in temperature if 3
...

Use the graph
...
°C [2]
(f)

Calculate the change in thermal energy when 3
...


3

Use the formula:
Change in thermal energy (J) = 4
...
02 g

Change in thermal energy =
...
The rest of the space
contains electrons
...

Particle

Relative Mass

Relative Charge


...



...



...


Proton
Neutron
Electron
[3]
(b) A student builds a model of an atom
...
7 cm to represent the nucleus in the model
...
Calculate the diameter of the model of the atom
...


Diameter of model =
...

Complete the table to show the number of each particle present in a phosphorus atom and a
sodium ion
...

+

Phosphorus atom, P

Sodium ion, Na


...



...



...


Number of Protons
Number of Neutrons
Number of Electrons
[3]
© OCR 2024

7
(d) The properties of elements depend on the electron arrangements of their atoms
...
8
...

The electron arrangement of fluorine is 2
...

Explain why magnesium is a metal and fluorine is a non-metal
...


...


...

Electrons from outer shell of metal atoms
–

–

–

–

–

–

+ – + –+ –+ – + –
+ – +
+ – +
–
–

+
–

–

+–

–

–

+

+

+

–

+

–

–

+– +–

+

–
–

–

+

–

––

–

–

–

–

– –

+

+

+

+

+

Metal ions
(a) Explain why metals are good electrical conductors, malleable, and have high melting points
...


...


...


...

In one experiment, they add a piece of magnesium to a blue aqueous solution of copper ions
...

Mg(s) + Cu

2+
(aq)

2+
Cu(s) + Mg (aq)

Explain how this reaction shows that magnesium is more reactive than copper
...


...


...


...

Most reactive


...


...

[2]

© OCR 2024

Turn over

10
5

The particle models for the different states of matter are shown
...

1
...

2
...

[2]
(b) The table gives some information about the movement and arrangement of particles for the
different states of matter
...

Movement of Particles

Arrangement of Particles
1 Regular

Solid


...

2
...

2
...


...


...
[2]

(d) Sulfur dioxide has a melting point of –73 °C and a boiling point of –10
°C
...
[1]

© OCR 2024

Turn over

12
6

A student wants to find the concentration of a sodium hydroxide solution
...
010 mol / dm dilute hydrochloric acid
...

Include an explanation of how this method gives high quality data
...


...


...


...


...


...


...

Titration
3
Volume of Acid Added (cm )

(i)

1

2

3

4

5

27
...
4

25
...
2

25
...


...
Give your answer to 1 decimal place
...
cm [3]

(iii) The student’s teacher states that the volume of the hydrochloric acid needed to react with
3
the sodium hydroxide should be 25
...

Explain what the student’s results show about the accuracy and precision of their experiment
...


...


...

N2(g) + 3H2(g)

(a)
(i) Define this symbol

2NH3(g)


...
[1]

(ii) Explain why reactions like this never give a 100% yield
...


...

The graph shows the effect of temperature and pressure on the yield of ammonia
...
Use words from the list
...


Increase


...



...

Temperature
...


...

Pressure
...


...

[4]
(c) Ammonium sulfate, (NH4)2SO4, is used by farmers as a fertiliser
...

Write a balanced symbol equation for the reaction
...


...


(a) Table 8
...

Table 8
...



...


[2]

(ii) Complete the word equation for the reaction between hydrochloric acid and sodium
hydroxide
...

[1]

+
(b) Table 8
...


Table 8
...
1

(i)

+
Concentration of H (aq)
3
(mol / dm )

1 × 10

0
...
001

1 × 10

–1
–2
–3

pH
1
2
3

+
Describe the relationship between H concentration and pH shown in Table 8
...



...


...
[2]
3
(ii) What is the pH of 0
...
[1]

© OCR 2024

17
(c) A student does an experiment to find the pH of different concentrations of dilute ethanoic
acid, CH3COOH
...

(i)

Describe how the student finds the pH using this test
...


...
3
...
3
Concentration of CH3COOH (aq)
3
(mol / dm )

pH

0
...
01

3

0
...


...
[1]

© OCR 2024

Turn over

18
9

Electrolysis is the decomposition of ionic compounds using electricity
...

Carbon anodes

Molten
aluminium
oxide

+
–

Carbon lining
as cathode
Molten
aluminium
(i)

Explain why the electrolysis must use molten aluminium oxide, and not solid aluminium oxide
...
[1]

(ii) The half equations show the reactions at the electrodes
...

Oxidised
...

Explanation
...

[3]
(iii) This is the balanced symbol equation for the decomposition of aluminium oxide by electrolysis:
2Al 2O3

4Al + 3O2

Calculate the mass of aluminium that will be produced when 100 g of aluminium oxide is used
...

Relative atomic masses: Al = 27
...
0
...
g [4]
© OCR 2024

19
(b) When aqueous sodium sulfate is electrolysed the products are hydrogen gas and oxygen gas
...

Include labels
...
State where the H ions and OH ions come from
...
[1]

(iii) Explain why hydrogen is formed instead of sodium
...


...


Electrode

Product

Half Equation

Anode (+)
Cathode (–)
[3]
END OF QUESTION PAPER
© OCR 2024

20
EXTRA ANSWER SPACE
If you need extra space use these lined pages
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© OCR 2024

22

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OCR qualifications include
AS/A Levels, Diplomas, GCSEs, Cambridge Nationals, Cambridge Technicals, Functional Skills,
Key Skills, Entry Level qualifications, NVQs and vocational qualifications in areas such as IT,
business, languages, teaching/training, administration and secretarial skills
...
OCR is a not-for-profit organisation; any surplus made
is invested back into the establishment to help towards the development of qualifications and
support, which keep pace with the changing needs of today’s society
...
It shows the basis on which marks were awarded by examiners
...

All examiners are instructed that alternative correct answers and unexpected approaches
in candidates’ scripts must be given marks that fairly reflect the relevant knowledge and
skills demonstrated
...

© OCR 2024

Oxford Cambridge and RSA Examinations

J260/06

Mark scheme

June 2024

MARKING INSTRUCTIONS
PREPARATION FOR MARKING
RM ASSESSOR
1
...


2
...
These are available in RM Assessor
...


Log-in to RM Assessor and mark the required number of practice responses (“scripts”) and the required number of
standardisation responses
...


Mark strictly to the mark scheme
...


Marks awarded must relate directly to the marking criteria
...


The schedule of dates is very important
...
If you experience problems, you must contact your Team Leader (Supervisor) without delay
...


If you are in any doubt about applying the mark scheme, consult your Team Leader by telephone, email or via the RM Assessor
messaging system
...


Mark scheme

June 2024

Work crossed out:
a
...


if a candidate crosses out an answer to a whole question and makes no second attempt, and if the inclusion of the answer does not
cause a rubric infringement, the assessor should attempt to mark the crossed out answer and award marks appropriately
...


Always check the pages (and additional objects if present) at the end of the response in case any answers have been continued there
...


7
...
Award NR (No Response)
-if there is nothing written at all in the answer space
-OR if there is a comment which does not in any way relate to the question (e
...
‘can’t do’, ‘don’t know’)
-OR if there is a mark (e
...
a dash, a question mark) which isn’t an attempt at the question
...


8
...
Please refer to
these comments when checking your practice responses
...

If you have any questions or comments for your Team Leader, use the phone, the RM Assessor messaging system, or email
...


Assistant Examiners will send a brief report on the performance of candidates to their Team Leader (Supervisor) via email by the end of the
marking period
...
Constructive
criticism of the question paper/mark scheme is also appreciated
...


Mark scheme

June 2024

For answers marked by levels of response:
Read through the whole answer from start to finish, using the Level descriptors to help you decide whether it is a strong or weak answer
...
Using a ‘best-fit’ approach based on the skills and science content evidenced within the
answer, first decide which set of level descriptors, Level 1, Level 2 or Level 3, best describes the overall quality of the answer
...

The lower mark should be awarded where the level descriptor has been evidenced but aspects of the communication statement (in
italics) are missing
...

The communication statement determines the mark within a

level
...


Mark scheme

Annotations available in RM Assessor

Annotation

Meaning
Correct response
Incorrect response
Omission mark
Benefit of doubt given
Contradiction
Rounding error
Error in number of significant figures
Error carried forward
Level 1
Level 2
Level 3
Benefit of doubt not given
Noted but no credit given
Ignore

5

June

J260/06
2024
12
...

Annotation

Meaning

/

alternative and acceptable answers for the same marking point



Separates marking points

DO NOT ALLOW

Answers which are not worthy of credit

IGNORE

Statements which are irrelevant

ALLOW

Answers that can be accepted

()

Words which are not essential to gain credit

__

Underlined words must be present in answer to score a mark

ECF

Error carried forward

AW

Alternative wording

ORA

Or reverse argument

6

June

J260/06
13
...
This material includes:
•

the specification, especially the assessment objectives

•

the question paper

•

the mark scheme
...

You should ensure also that you are familiar with the administrative procedures related to the marking process
...
If you are examining for the first time, please read carefully Appendix 5 Introduction to Script Marking:
Notes for New Examiners
...
Your first point of contact is your Team Leader
...


AO1
...


AO1
...

Apply knowledge and understanding of scientific ideas and scientific enquiry, techniques and procedures
...
1

Apply knowledge and understanding of scientific ideas
...
2

Apply knowledge and understanding of scientific enquiry, techniques and procedures
...
1

Analyse information and ideas to interpret and evaluate, make judgements and draw conclusions and develop and improve
experimental procedures
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


AO3
...


8

J260/06

Mark scheme

1

AO
element
2
...
54 x 10-10
Silver (atom) / 2
...
10 x 10-9
Platinum (nanoparticle) / 1
...
2

As size/particle gets bigger, (surface area to volume)

2

3
...
54 x
silver (atom) / 2
...
ORA

✓

OR

ALLOW size increases 10 times ratio
decreases to/by a tenth/words to the effect
of going up and down by factor of 10

Size increase ten times, (surface area to volume)
ratio decreases ten times/size and ratio are inversely
proportional ORA

(c)

✓✓

First check the answer on answer line
If answer = 600 (nm2) award 3 marks
Length of one face = 10nm

✓

2
...
3a
IGNORE amount of acid/solid

✓

ALLOW temperature (change)
...

Any two points correctly plotted = 1 mark
ALLOW +/- Half square tolerance
Line must start at 0/22 and end at 5/59
...

ALLOW ECF from incorrectly plotted points
IGNORE line outside grid

✓

(b)

All points correctly plotted

(c)

Line of best fit

(d)
(e)

Y=mx+c

✓✓

✓

✓

First check the answer on answer line
o
If answer = 28
...
5oC

1

2
...
1a
3
...
7 (J) award 3 marks
Mass of hydrochloric acid: 50 x 1
...
2 x 28
...
2

✓

(Change in temperature: 50
...
0) = 28
...
2

ALLOW 50-51 oC
ALLOW 28-29 oC
ALLOW minimum of 2 significant figures
ALLOW 3 marks if answer is correct for
answer to part e
...
7(J)

Marks

June 2024
AO
element

Guidance
ALLOW correct evaluation from mp2
IGNORE incorrect rounding on answer line if
correct evaluation given in working
...
1

Guidance
6 correct = 3 marks
5 or 4 correct = 2 marks
3 or 2 correct = 1 mark
ALLOW

Particle

Relative
mass

Relative charge

Proton

1

+1

Neutron

1

0

Particle

Electron

Negligible /
1/1800/
1/2000

-1

Proton



Neutron
Electron

(b)

First check the answer on answer line

2

Number of protons

15

11

Number of neutrons

16

12

Number of electrons

15

10





(d)



Na+


Electrons

Neutrons

Protons

Magnesium small number electrons in outer shell
AND fluorine large number



Metals/magnesium lose electrons( to give full outer
shell) AND Non-metals/fluorine gains

+1
+1
0 / very
small/tiny/
0
...
2
2
...
7 x 105/ 670000 for 1 mark

 

0
...
7 x 103/ 6700 (m)

Relative

mass

ALLOW ECF in MP2 for incorrect conversion/

If answer = 6700 (m) award 2 marks
Conversion: (6
...
067

Relative



12

3

2
...
1

IGNORE magnesium has 2 electrons in outer
shell AND fluorine has 7 electrons in outer
shell unless reason why 2 electrons are lost/1
electron gained is given/linked to small/large
elsewhere
...
1

✓
ALLOW atoms/layers

High melting point – strong attraction/force between

(b)

✓

Magnesium loses electrons/is oxidised
...


(c)

(i)

Cu

(ii)

✓

✓

2

2
...
2

2

3
...

IGNORE free/carry the charge
...

DO NOT ALLOW atoms, molecules, ionic
bonds etc
ALLOW Magnesium gives electrons to copper
ions
...

Mg most reactive and silver least reactive = 1
mark
Iron more reactive than copper = 1 mark

J260/06

Mark scheme

Question
5

(a)

Answer

2

AO
element
1
...
1

Marks

Any two from:
Assume (inelastic) spheres/not actual shape





June 2024
Guidance

Don’t show true scale/actual size (of particles)/actual
space between particles



Don’t show interactions/attractions/bonds between



particles/atoms/molecules
Don’t show movement/collisions of particles

Don’t show electron etc





(b)

Solid
Liquid

Movement of
Arrangement of
particles
particles
Vibration (about
a fixed point) 
Moving/sliding
past each other

Close together




(c)

ALLOW irregular
2



Particles gain (kinetic) energy
(and) move faster/move apart/move more



Particles move further apart/move more



ALLOW atoms/molecules/ions for particles
DO NOT ALLOW idea of moving apart if
clearly referring to solid to liquid change



Energy breaks/weakens force between particles

Gas

1
...






IGNORE temperature/heating/heated



1

14

3
...

Level 3 (5–6 marks)
Detailed description of titration method AND
explanation of how this gives quality data
...
The information
presented is relevant and substantiated
...

OR
Some details of titration method AND some
explanation of how this gives quality data
...
The information presented is relevant and
supported by some evidence
...

There is an attempt at a logical structure with a line
of reasoning
...

0 marks
No response or no response worthy of credit
...
2

Guidance
AO1
...
2

3

3




ALLOW Student has added too much
acid/has gone past colour change/air bubble
in burette
ALLOW 2 marks if answer on answer line is
25
...
3 (cm ) award 3 marks
(25
...
3 + 25
...
2 =) 101
...
2 x 2

(101
...
275

= 25
...
3cm3) is not/is close to true value



(25
...
2
3
...
4 + 25
...
2 + 25
...
2 =) 128
...
3 ÷ 5 =) 25
...
7 (cm3) (1dp)
ALLOW ECF from bii
ALLOW Accuracy –good because
experimental result (25
...
8cm3) / is not good because they
are not the same

Precision – good because (all but rough/titration 1)
close together





ALLOW Precision – if all 5 readings
considered then not good because readings



not all close together

16

J260/06

Mark scheme

Question
7

(a)

Answer
Reversible 

(ii)

Ammonia reacts back to hydrogen and nitrogen /
products react to form reactants

(b)

(i)



(Increase in temperature) decreases the yield
...


Catalyst yield – no effect
Catalyst rate – increase

(ii)

1

AO
element
1
...
1

4

3
...


4





ALLOW reaction goes both ways
IGNORE equilibrium
ALLOW go back to/turn back into

1
...


IGNORE more/more chance of collisions
unqualified by reference to successful/effective
e
...
more frequent alone

Pressure

DO NOT ALLOW either mark if refers to move
more vigorously/faster/have more energy
...


More frequent collisions
...
1 x 2



Temperature:

June 2024

2 NH3 (g)





ALLOW correct references to numbers of
particles in volume/area/less space



+ H2SO4(aq) → (NH4)2SO4 (aq)

2



2
...
2

Balancing

State symbols

17

ALLOW increased chance of
collisions/particles collide more often
IGNORE more collisions unqualified by idea of
time
...


J260/06

Mark scheme

Question
8

(a)

Answer
(i)

(sulfuric acid + copper oxide) Copper sulfate



(calcium carbonate, calcium nitrate) Nitric acid

(b)

2

AO
element
2
...
2

ALLOW hydrogen oxide
IGNORE H2O

2

2
...


1
1

2
...
2

1

1
...
g red
is pH 1/green is pH7
IGNORE pH machine

J260/06

Mark scheme

Question
9

(a)

Answer
(i)

liquid

(ii)





Oxidised - O2-/oxide ions/oxygen ions
Reduced - Al3+/aluminium ions

1

AO
element
1
...
2

Marks

Ions cannot move in solid /Ions can only move in





June 2024

Explanation – Oxidation is loss of electrons AND
reduction is gain of electrons

(iii) First check the answer on answer line
If answer = 52
...
94117647… (g)

= 52
...
2 x 3





ALLOW multiples e
...
204
ALLOW multiples e
...
204/108 provided they
are consistent
ALLOW ECF from incorrect relative formula
mass of aluminium oxide
ALLOW ECF in evaluation if candidate has
done a multiplication and division using values
for aluminium oxide, aluminium and mass of
aluminium oxide used
...
2

19

ALLOW sf mark if it is correct from incorrect
evaluation

J260/06
(b)

Mark scheme
(i)

3

June 2024
1
...


Solution shown in a container in contact with
electrodes/ label showing electrolyte/sodium sulfate
solution in container



Test tubes over electrodes/label indicating where test
tubes should be

MAX 2 marks for drawing with no labels/labels
with no drawing

ALLOW a gas syringe/tube attached to whole
container (i
...
has not collected gases
separately)/suitable label indicating a gas
syringe or tube
DO NOT ALLOW sealed top to container in the
given diagram



Solution in test tubes shown by a surface in the tube



Water/H O
/label

2
(ii)
(iii) Sodium more reactive (than hydrogen) / sodium
higher in reactivity series (than hydrogen)/hydrogen
ions gain electrons more readily (than sodium ions)

1
1

1
...
2

3

2

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