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COMBINED SCIENCE A

OCR 2024
GCSE Combined Science A
(Gateway Science)
J250/10 Chemistry (Higher Tier)
With Marking Scheme Merged

Oxford Cambridge and RSA

Tuesday 11 June 2024 – Morning
GCSE (9–1) Combined Science A
(Gateway Science)
J250/10 Chemistry (Higher Tier)
Time allowed: 1 hour 10 minutes

H

You must have:
• a ruler (cm/mm)
• the Data Sheet for GCSE (9–1) Combined Science A
(Chemistry) (inside this document)
You can use:
• a scientific or graphical calculator
• an HB pencil
*

J

2

5

0

1

0

*

Please write clearly in black ink
...

Centre number

Candidate number

First name(s)
Last name
INSTRUCTIONS
• Use black ink
...

• Write your answer to each question in the space provided
...
The question numbers must be clearly shown
...

• Where appropriate, your answer should be supported with working
...

INFORMATION
• The total mark for this paper is 60
...

• Quality of extended response will be assessed in questions marked with an asterisk (*)
...

ADVICE
• Read each question carefully before you start your answer
...

Write your answer to each question in the box provided
...
copper oxide + carbon

copper + carbon

dioxide What is the role of the carbon?
A It is a catalyst
...
C
It oxidises the copper oxide
...


Your answer
2

[1]

A teacher investigates some reactions of chlorine
...

B Chlorine is inert
...
D
Chlorine is toxic
...

Key:
Supply
Demand

Relative amount
of fractions

Gases Petrol Paraffin Diesel Fuel oil
Which fractions are most likely to be cracked to make the supply match the demand?
A

Diesel and fuel oil

B

Gases and petrol

C

Paraffin and fuel oil

D

Petrol and diesel

[1]

Your answer

© OCR 2024

Turn over

4
6

Acid rain is a dilute solution of a weak acid
...

The graph shows how the mass of the reactants changes during the reaction
...

What is the balanced half equation for the reaction of fluorine when it reacts with sodium?
–
A F+e

B F

F 

–
–
F  + e

–
C F2 + 2e

D F2

–

2F 

2F 
–

–

–
+ 2e

Your answer

[1]

10 Methanol, CH3OH, can be made by reacting carbon monoxide, CO, with hydrogen, H2
...

Which change in temperature and pressure will move the position of equilibrium to the right?
Change in temperature

Change in pressure

A

decreases

decreases

B

decreases

increases

C

increases

decreases

D

increases

increases

[1]

Your answer

© OCR 2024

Turn over

6
Section B
11 Aluminium is extracted from a rock called bauxite which contains aluminium oxide
...

Mining

Purification

Extraction

Production

Use

Recycling

Disposal

(a) Give one reason why a life-cycle assessment is carried out
...


...

1
...

2
...

[2]
(c) 18% of the bauxite rock is turned into aluminium
...
Give your answer to 2 significant figures
...
kg [3]
(d) During the purification, aluminium oxide, Al 2O3, is produced from aluminium hydroxide, Al
(OH)3
...



...
H2O
[2]

© OCR 2024

Turn over

8
(e) Aluminium is extracted from aluminium oxide, Al 2O3, by electrolysis
...


2Al 2O3

4Al + 6O2

A student thinks that this reaction is an example of reduction
...


...
[1]

(ii) Extracting aluminium by electrolysis is expensive
...

True

False

Aluminium oxide is melted at a high temperature
...

The electrolysis uses large amounts of electricity
...

Explain why aluminium oxide does not react with carbon
...


...
The diagram shows the equipment they use
...

Explain how the student’s equipment separates water from muddy water
...


...


...


...


...

(a) Which statement describes why crude oil is called a feedstock for the petrochemical industry?
Tick one (3) box
...

It’s a source of environmentally friendly fuels
...

[1]
Table 13
...

Table 13
...


(b) Calculate the percentage of fraction W found in crude oil
...
1
...

Complete Table 13
...
1
...
2
Number of carbon atoms
in the molecules
1–4
5–11
12–14

Fraction


...


...
1 which has the strongest
intermolecular forces
...
[1]

(e) Many of the hydrocarbons in crude oil are alkanes
...


...


...

The diagram shows the equipment they use
...

Measure and record the initial temperature of the copper sulfate solution
...


•

Record the highest temperature reached
...

Metal

Initial temperature
(°C)

Highest Temperature
(°C)

Temperature change
(°C)

Tin

34
...
8

Zinc

43
...
5

Iron

29
...
6

Magnesium

47
...
0

(a) Calculate the lowest initial temperature of the copper sulfate solution
...
°C [1]

© OCR 2024

13
(b) Use the student’s results to list the metals in the order of reactivity obtained by the student
...


...

Least reactive
...

(i)

The student thinks that the error could be because they added incorrect masses of each metal
...
[1]

(ii) Another student thinks that the error could be because the iron powder used is old and its
surface has been oxidised
...


...


...
[2]

(d) The balanced symbol equation for the reaction between magnesium and copper sulfate solution
is:
Mg(s) + CuSO4(aq)

MgSO4(aq) + Cu(s) The

reaction can be written as an ionic equation
...


Mg + Cu

2+


...

(a) What is the percentage of carbon dioxide found in the Earth’s atmosphere today?
Tick one (3) box
...
04%
0
...

The graph shows the carbon dioxide in the atmosphere and carbon dioxide emissions from
1750 – 2020
...


...


...
[2]

(ii) Give one reason for the change in carbon dioxide emissions after 1960
...


...

(i)

Describe how an increase in carbon dioxide in the atmosphere is causing global warming
...


...


...


...
[1]

© OCR 2024

Turn over

16
16* A student investigates the rate of reaction between magnesium and an excess of dilute
hydrochloric acid
...
In the experiments they use the same length of magnesium
but change one other variable
...

Experiment

Time for the magnesium
to react (s)

1

37

2

26

3

19

Describe the method the student used to get these results, including the variable they may have
changed and the variables they controlled
...


...


...


...


...


...


...

The table shows the diameter of atoms and arrangement of electrons for the first three
elements in Group 1
...
04 × 10
–10
3
...
54 × 10

Arrangement of
electrons
2, 1
2,8,1
2,8,8,1

(a) Describe and explain the trend in the diameter of atoms of the elements in Group 1
...


...
[2]

(b) Rubidium is the element below potassium in Group 1
...


...


...


...


...


...
[4]

END OF QUESTION PAPER

© OCR 2024

18
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© OCR 2024

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POST EXAM CORRECTION

Tuesday 11 June 2024 – Morning
GCSE (9–1) Combined Science
A (Gateway Science)

J250/10 Chemistry (Higher Tier)
If you wish to use the published question paper as practice material, please make the
following correction:

Turn to page 8 of the question paper and look at question 11(e)(i)
...

The equation should now read:
2Al 2O 3

4Al

+ 3O2

If you have any queries, please call our Customer Support Centre on 01223 553998 or
email support@ocr
...
uk

© OCR 2024 Jun24/post-exam correction

Higher
GCSE
Combined Science Chemistry A Gateway Science
J250/10: Paper 10 (Higher Tier)
General Certificate of Secondary Education

Mark Scheme for June 2024

Oxford Cambridge and RSA Examinations

OCR (Oxford Cambridge and RSA) is a leading UK awarding body, providing a wide range of
qualifications to meet the needs of candidates of all ages and abilities
...


It is also responsible for developing new specifications to meet national requirements and
the needs of students and teachers
...

This mark scheme is published as an aid to teachers and students, to indicate the requirements
of the examination
...
It does not
indicate the details of the discussions which took place at an examiners’ meeting before
marking commenced
...

Mark schemes should be read in conjunction with the published question papers and the
report on the examination
...


Make sure that you have accessed and completed the relevant training packages for on-screen marking: RM Assessor Online Training; OCR
Essential Guide to Marking
...


Make sure that you have read and understood the mark scheme and the question paper for this unit
...


3
...


MARKING
1
...


2
...


3
...
It is essential that you meet the RM Assessor 50% and 100% (traditional 50% Batch 1 and
100% Batch 2) deadlines
...


4
...


2

J250/10
5
...


where a candidate crosses out an answer and provides an alternative response, the crossed out response is not marked and gains
no marks

b
...


6
...
If
the candidate has continued an answer there, then add the annotation SEEN to confirm that the work has been seen
...


There is a NR (No Response) option
...
g
...
g
...

Note: Award 0 marks – for an attempt that earns no credit (including copying out the question)
...


The RM Assessor comments box is used by your Team Leader to explain the marking of the practice responses
...
Do not use the comments box for any other reason
...


9
...
The report should contain notes on particular strengths displayed as well as common errors or weaknesses
...


3

J250/10
10
...
The
indicative scientific content in the Guidance column indicates the expected parameters for candidates’ answers, but be prepared to recognise and
credit unexpected approaches where they show relevance
...


Once the level is located, award the higher or lower mark:
The higher mark should be awarded where the level descriptor has been evidenced and all aspects of the communication statement
(in italics) have been met
...

In summary:
The skills and science content determines the level
...
Level of response question on this paper is 16
...


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 2024

J250/10

Mark Scheme

June 2024

Abbreviations, annotations and conventions used in the detailed Mark Scheme (to include abbreviations and subject-specific conventions)
...


Mark Scheme

June 2024

Subject-specific Marking Instructions

INTRODUCTION
Your first task as an Examiner is to become thoroughly familiar with the material on which the examination depends
...


You should ensure that you have copies of these materials
...
These are set out in the OCR
booklet Instructions for Examiners
...

Please ask for help or guidance whenever you need it
...


7

J250/10

Mark Scheme

June 2024

The breakdown of Assessment Objectives for GCSE (9-1) in Combined Science A:
Assessment Objective
AO1

Demonstrate knowledge and understanding of scientific ideas and scientific techniques and procedures
...
1

Demonstrate knowledge and understanding of scientific ideas
...
2
AO2

Demonstrate knowledge and understanding of scientific techniques and procedures
...


AO2
...


AO2
...


AO3
AO3
...

Analyse information and ideas to interpret and evaluate
...
1a

Analyse information and ideas to interpret
...
1b

Analyse information and ideas to evaluate
...
2

Analyse information and ideas to make judgements and draw conclusions
...
2a

Analyse information and ideas to make judgements
...
2b

Analyse information and ideas to draw conclusions
...
3

Analyse information and ideas to develop and improve experimental procedures
...
3a

Analyse information and ideas to develop experimental procedures
...
3b

Analyse information and ideas to improve experimental procedures
...
g
...

Question

Answer

Marks

AO
element

1

D

1

1
...
2

3

B

1

1
...
1

5

C

1

2
...
1

7

B

1

2
...
2

9

C

1

2
...
1

Guidance

J250/10
Question

Mark Scheme
Answer

Marks

11 (a)

1

June 2024
AO
Guidance
element
1
...
g
...
g
...
2

Idea that recycling conserves (raw) materials / (natural)
resources

IGNORE cost / saves the planet / helps
environment / littering
ALLOW reduce the need to extract finite
resources/conserve finite resources
ALLOW less fossil fuels used



Idea that recycling reduces environmental impact of

ALLOW less impact from mining on habitats / less

mining

removal trees / less visual/noise pollution







Idea that recycling uses less energy
Idea that recycling releases less named polluting
substances into the environment

e
...
, carbon dioxide/greenhouse gases
ALLOW reduces climate change / reduces global
warming / less toxic waste



Idea that less / no waste (products) /less (goes into)
landfill
(c)



First check answer on the answer line
If answer = 1400 (kg) award 3 marks
7500 x

18

3



2 x 2
...
2



3H O
2Al(OH)3

2

2

11

2 x 2
...
To make sure all candidates were treated fairly,
we have awarded the mark to all candidates for this question
...
1b
ALLOW aluminium ions / Al 3+ gain electrons
IGNORE oxygen has been separated from
aluminium
DO NOT ALLOW aluminium loses oxygen / gains
electrons
(ii)

2
True

Aluminium oxide is melted at a high temperature
...


The electrolysis uses large amounts of electricity
...
2




(iii) Aluminium is more reactive (than carbon) / ORA 

1

12

1
...
2

Guidance

The sun heats up the (muddy) water / metal tin 
Metal tin transfers heat (from sun) to (muddy) water



The water evaporates 

ALLOW heat from sun causes water to
evaporate for 2 marks for MP1 and 3
ALLOW idea liquid changes to vapour / gas
IGNORE muddy water evaporates

(The water / vapour rises upwards and) touches the

piece of glass

ALLOW gas (particles) touches piece of glass
IGNORE muddy water

The water vapour cools and condenses 

ALLOW idea that vapour / gas cools and changes
to liquid
IGNORE steam
ALLOW water vapour hits cold glass and
condenses for 2 marks for MP4 and MP5

The curve of the glass means water (droplets) form at
lowest point / water runs down (and drops into glass)



Mud particles do not evaporate / are left behind (in metal
tin)



13

J250/10

Mark Scheme

Question

Answer

Marks

13 (a)

1

June 2024
AO
Guidance
element
1
...

It’s a source of environmentally friendly fuels
...


(b)

30






1

(c)

2
Number of carbon
atoms in the
molecules

Name of fraction

1-4

X

5-11

U

12-14

Z

2
...
2b All 3 correct = 2 marks
Any 1 or 2 correct = 1 mark



V

(d)
(e)

(i)



CnH2n+2



1

2
...
1

ALLOW H2n+2 Cn
DO NOT ALLOW superscripts e
...
, CnH2n+2

(ii)

C14H30



1

2
...
g
...
2

1

3
...
1b



(i)

Balance/scales

(ii)

Temperature change lower than expected



Less iron/metal available to react (with copper sulfate)

(d)

AO
Guidance
element
2
...
1 (°C) 

Iron
(c)

Marks

June 2024



Mg + Cu2+ → Mg2+ + Cu


1
...
1

ALLOW weighing scale
IGNORE digital scale/scale
ALLOW highest temperature lower than expected
Answers must refer to idea of reacting
ALLOW iron oxide / rust forms a barrier (so less
reaction occurring)
ALLOW Mg2+ and Cu in either order
DO NOT ALLOW incorrect placements of
superscript e
...
, Mg2+

15

J250/10

Mark Scheme

Question

Answer

0
...
1

2

2 x 3
...
4%

4%


(b)

(i)
As carbon dioxide emissions increase, carbon dioxide in

IGNORE positive correlation



atmosphere increases



(Carbon dioxide) emissions have risen faster (than
atmospheric carbon dioxide) in the last 100 years
(ii)

(c)



Idea that the rise in carbon dioxide emissions is due to an
increase in use of fossil fuels





(i)
Carbon dioxide traps heat in atmosphere

ALLOW last 80 - 120 years


1

1
...
1
ALLOW carbon dioxide absorbs infrared
radiation/reemits absorbed heat
DO NOT ALLOW ozone layer

Increase in trapped heat increases (global) temperature

Answer must refer to both ideas of increasing
IGNORE increases global warming



(ii)

Reduce use of fossil fuels / use biofuels / use renewable
energy sources / idea of carbon capture

ALLOW ideas such as more industry / more

1



16

1
...
g
...

Level 3 (5–6 marks)
Describes in detail the method used by the student
AND
Describes the variable the student changed and links
this to the results from experiments 1 – 3
AND
Describes in detail the variables the student controlled

6

June 2024

AO
Guidance
element
2
...
3a Analyse information and ideas to
3
...
g
...
The information presented is
relevant and substantiated
...
2 Apply knowledge and understanding of
scientific enquiry, techniques and procedures

Level 2 (3–4 marks)
Reasonable description of the method used by the
student
AND
Describes the variable the student changed from
experiment 1 – 3
AND
Describes a variable the student controlled

Describes the variable the student changed e
...
:
• increased temperature from experiment 1 to 3
• increased concentration of acid from
experiment 1 to 3

There is a line of reasoning presented with some
structure
...


• same concentration of acid if temperature
changed
• same temperature of acid if concentration
changed

Describes the variables the student controlled
e
...
:
• same volume of acid

17

J250/10

Mark Scheme
Level 1 (1–2 marks)
Limited description of the method used by the student
OR
Describes the variables the student changed from
experiment 1 to 3
OR
Describes variable(s) the student controlled

June 2024
ALLOW answers based on only changing surface
area or using a catalyst level 1 marks only for
method and control variable points

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

0 marks
No response or no response worthy of credit
...
1a
1
...
55 x 10-10 - 5
...
2a
ORA throughout





Outer electron/shell further from the nucleus (with



1

3
...
1

ALLOW more energy levels/shells
ALLOW outer electron in a higher energy level

1

1
...
1

increased diameter/reactivity)

Less attraction from nucleus/protons (with increased
diameter/reactivity)



Loses electron(s) more easily (with increased
diameter/reactivity)



ALLOW outer electron in a higher energy level /
further from the nucleus
IGNORE more electrons



IGNORE loses electrons faster
MPs 2, 3 and 4 must be comparative

19



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