Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

COMBINED SCIENCE A

OCR 2024
GCSE Combined Science A
(Gateway Science)
J250/04 Chemistry (Foundation Tier)
With Marking Scheme Merged

Oxford Cambridge and RSA

Tuesday 11 June 2024 – Morning
GCSE (9–1) Combined Science A
(Gateway Science)
J250/04 Chemistry (Foundation Tier)
Time allowed: 1 hour 10 minutes
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

F
*

J

2

5

0

0

4

*

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
...

Which product of burning fossil fuels is an example of a particulate?
A Carbon
B Carbon monoxide C
Nitrogen dioxide D
Sulfur dioxide
Your answer

© OCR 2024

[1]

3
4

The word equation shows how iron is extracted from iron oxide
...


Mass (tonnes)

Iron oxide

Carbon

3200

360

Iron

Carbon dioxide
1320

What is the mass of iron produced?

A

1880 tonnes

B

2240 tonnes

C

2840 tonnes

D

4880 tonnes

Your answer

5

[1]

Scientists think the Earth’s oxygen-rich atmosphere developed due to photosynthesis by
plants
...

The table shows the amounts of different gases released by a volcano
...
The table shows their results
...


B

Copper is the most reactive metal
...


D

Tin is the most reactive metal
...
Which metal forms positive ions most easily?

Metal A

Metal B

Metal C

Metal D

Your answer

9

[1]

Carbon reacts with copper oxide to produce
copper
...

B It neutralises the copper oxide
...
D It
reduces the copper oxide
...

Why is it important that the teacher does not breathe in chlorine?
A Chlorine is highly flammable
...

C Chlorine is strongly alkaline
...

Your answer

© OCR 2024

[1]

7
BLANK PAGE

PLEASE DO NOT WRITE ON THIS PAGE

© OCR 2024

Turn over

8
Section B
11 A student does some experiments to separate water from muddy water
...
11
...

Fig
...
1

Muddy water

Water

(i)

What is the name of this separation technique?

...

Why is the student not sure that the water produced is potable?

Tick (3) two boxes
...

The experiment takes too long
...

The water may contain tiny particles of mud
...
11
...

Fig
...
2

A cold, curved
piece of glass

Large metal tin

Glass beaker

Muddy water
Water

The student leaves the equipment in a sunny place
...

The statements are not in the correct order
...


B

The sun heats up the muddy water
...


D

The water vapour cools and condenses
...


F

The water vapour touches the cold piece of glass
...

B

E

A
[2]

© OCR 2024

Turn over

10
12 This question is about Groups 1, 7 and 0 in the Periodic Table
...
1
...
1
Properties

Group 1

Group 7

Group 0

They are non-metals
...

They form coloured gases
...

They react these with water
...


Table 12
...

Complete Table 12
...

Table 12
...


...


Time to disappear
(s)
4
21
12
[2]

© OCR 2024

11
(c) The teacher also does an experiment to show that the order of reactivity going down Group 7 is:

Chlorine
Bromine

reactivity decreases

Iodine

They react gases of each Group 7 element with small pieces of hot iron and write down
their observations
...
3 shows their results
...
3 by writing chlorine, bromine and iodine in the correct spaces
...
3
Group 7 element

...


...

The iron glows very brightly
...

[2]

(d) Table 12
...

Table 12
...


...
Use the information in Table 12
...


...

(a) The table shows the percentages of different gases found in the Earth’s atmosphere
...
95

Carbon dioxide

0
...
92

Calculate the percentage of nitrogen in the Earth’s atmosphere
...
% [2]
(b) Nitrogen reacts with hydrogen to form ammonia
...


...


...

Pressure
(atmospheres)

Percentage of
ammonia (%)

0

0

100

22

200

40

300

54

400

62

500

66

(i) Plot the data from the table on the graph
...


[2]

(ii) Draw the curve of best fit
...

(i)

Oxides of nitrogen responsible for acid rain are given the formula
NOx
...
[1]

(ii) Normal rain water is slightly acidic
...

Test
...

Result
...


...

(a) Complete the sentence about crude oil
...

Crude oil is a compound / feedstock / renewable resource used by the petrochemical industry
...

Fractionating Column
Gases

Petrol
Kerosene
Diesel oil
Fuel oil
Crude oil
vapour
Bitumen
(i)

Which state symbol describes the crude oil as it enters the fractionating column?
Tick (3) one box
...


© OCR 2024

[1]

17
(c) The table shows the boiling point of four hydrocarbons
...
[1]

(ii) Which of the hydrocarbons P, Q, R or S has the largest molecules?

...

The equation shows the cracking of hydrocarbon X
...
[1]

(ii) Which homologous series of hydrocarbons does C6H14 belong to?

...

Suggest the general formula of the homologous series that contains C2H4
...

CnHn

CH
n

C H
2n

2n

n

[1]

© OCR 2024

Turn over

18
15* A student investigates the rate of reaction between pieces of marble chips and an excess of
dilute hydrochloric acid
...

Carbon dioxide gas

Gas syringe

Marble chips

Dilute hydrochloric acid

The student measures the total volume of carbon dioxide gas produced every minute until the
reaction finishes
...


Experiment 1
40
Experiment 2

30
Total volume of
carbon dioxide
3
(cm )
20
10

00

1

2

3

4

5

Time (min)

© OCR 2024

6

7

8

9

19
Which experiment has the greater rate of reaction?
Explain your answer by including:
•
•
•

information from the graph
a description of how the experiments might be different
ideas about the reacting particle model including particles and their collisions
...


...


...


...


...


...


...

The diagram shows information from a life-cycle assessment for the manufacture and use
of aluminium products
...


...
[1]

© OCR 2024

21
(b) Give two reasons why the products should be recycled at the end of their useful life
...


...


...

Calculate the mass of aluminium that is extracted from 7500 kg of
bauxite
...


Mass of aluminium =
...
Complete the balanced symbol equation for the reaction
...
Al (OH)3

Al 2O3 +
...

(i)

This is the equation for the electrolysis of aluminium oxide
...

Explain why the student is correct
...


...

Which statements about why the electrolysis is expensive are true, and which are false?
Tick one (3) box in each row
...

The electrolysis produces impure aluminium
...

[2]
(iii) It would be cheaper if aluminium could be extracted by heating the aluminium oxide with carbon
...


...
[1]

END OF QUESTION PAPER

© OCR 2024

23
EXTRA ANSWER SPACE
If you need extra space use these lined pages
...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...


...

In the equation on the second line, cross out ‘6’ and replace with ‘3’
...
org
...
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

J250/04

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

Crossed Out Responses
Where a candidate has crossed out a response and provided a clear alternative then the crossed out response is not marked
...

Rubric Error Responses – Optional Questions
Where candidates have a choice of question across a whole paper or a whole section and have provided more answers than required, then
all responses are marked and the highest mark allowable within the rubric is given
...
(The underlying assumption is that the candidate has penalised themselves
by attempting more questions than necessary in the time allowed
...

When a question requires candidates to select more than one option/multiple options, then local marking arrangements need to ensure
consistency of approach
...

Short Answer Questions (requiring only a list by way of a response, usually worth only one mark per response)
Where candidates are required to provide a set number of short answer responses then only the set number of responses should be marked
...
The remaining responses should not then be marked
...
(The underlying assumption is that the candidate
is attempting to hedge their bets and therefore getting undue benefit rather than engaging with the question and giving the most
relevant/correct responses
...
)

Longer Answer Questions (requiring a developed response)
Where candidates have provided two (or more) responses to a medium or high tariff question which only required a single (developed) response
and not crossed out the first response, then only the first response should be marked
...


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


Award No Response (NR) if:
• there is nothing written in the answer space
Award Zero ‘0’ if:
• anything is written in the answer space and is not worthy of credit (this includes text and symbols)
...


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
...


5

J250/04
11
...

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

7

J250/04
12
...
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
...


9

J250/04

Mark Scheme

June 2024

For answers to Section A if an answer box is blank ALLOW correct indication of answer e
...
, circled or underlined
...
1

2

B

1

1
...
1

4

B

1

1
...
1

6

A

1

2
...
1

8

C

1

2
...
2

10

D

1

1
...
2
2 x 3
...
2

C before F = 1 mark
F before D = 1 mark

Only small amounts of water are
produced
...

The water may contain
bacteria
...





(b)
B

→

C

→

E

→

F

→

D

→

A


11

J250/04

Mark Scheme

Question

Answer

Marks

12 (a)

3
Group
1
They are non-metals
...

They form coloured
gases
...
1 1 mark for each correct row

Group
0






(b)
Group 1 element

Time for piece of metal to
disappear
(s)

potassium

4

lithium

21

sodium

12

2

2 x 2
...
1

All 3 correct = 2 marks



(c)
Group 7 element

Observatio
n

bromine

The iron glows brightly
...


iodine

The iron only glows slightly
...
1a
ALLOW (become) higher / become less negative /
more positive
3
...
75 (%) award 2 marks
20
...
38 + 0
...
25

100 – 22
...
75

(b)

(i)

Contains ⇌ sign



2

June 2024
AO
Guidance
element
2 x 2
...
8
scores 1 mark


ALLOW ECF for incorrect addition if working
shown
1



1
...
1

ALLOW nitrogen + hydrogen in either order
ALLOW ⇌ instead of →

ALLOW nitrogen + hydrogen

ammonia

DO NOT ALLOW and or - in place of +
If a symbol equation is given it must be fully
balanced N2 + 3H2
(c)

(i)

All 4 points plotted correctly scores 2 marks



But
2 or 3 points plotted correctly scores 1 mark

2



14

2 x 2
...
2

Curve within 1 square of all the points including
the origin unless plotting is incorrect where best fit
curve should be judged
IGNORE line after 500 atmospheres
DO NOT ALLOW feathery line / multiple lines /
line drawn dot to do with a ruler / 1 square thick

(d)



(i)

2 / two

(ii)

Test: Idea of the use of universal indicator / pH meter

1



2

2
...
3a ALLOW pH probe / pH paper / pH indicator / pH
strip
DO NOT ALLOW other indicators for M1

Result: Idea that pH of acid rain is lower than normal

ALLOW pH is lower / pH lower than 5 / pH value

rainwater

3/4
ALLOW idea that universal indicator goes (more)
orange/red in acid rain





IGNORE universal indicator goes more yellow /
higher acid level / more acidic / orange in (normal)
rainwater
DO NOT ALLOW in (normal) rainwater/acid rain
universal indicator goes green / blue / purple

15

J250/04

Mark Scheme

Question
14

(a)

Answer

Marks

Crude oil is a compound / feedstock / renewable
resource used by the petrochemical industry
...
1





(g)

June 2024

1

1
...
2

(l)
(s)
(ii)



X drawn at the top of the column



ALLOW X anywhere above the petrol fraction
level including the exit pipe
DO NOT ALLOW X outside of the column or pipe

(c)

(d)

(ii)



Q

(i)

C10H22

(i)

R



1

3
...
2b

ALLOW 126

1

2
...
g
...
1

1

3
...

Level 3 (5–6 marks)
States that Experiment 1 has the greater rate with an
accurate explanation of graphical information
...


6

June 2024
AO
element
1
...
1 x 2
3
...

AO3
...
The information presented is
relevant and substantiated
...
g
...
1 Apply knowledge and understanding of
scientific ideas

Level 2 (3–4 marks)
States that Experiment 1 has the greater rate with clear
explanation of graphical information or conditions
...


Describes why Experiment 1 has the greater rate
because e
...
,
• it was carried out at a higher temperature
• the concentration of acid was higher
• the pieces of marble were smaller
• a catalyst was used

OR
States that Experiment 1 has the greater rate with some
explanation of graphical information or conditions
...


AO1
...
g
...


17

J250/04

Mark Scheme

June 2024
•

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


•

Level 1 (1–2 marks)
States that Experiment 1 has the greater rate
...

OR
States that Experiment 2 has the greater rate with
some explanation of conditions or why experiment 2
has the greater rate
There is an attempt at a logical structure with a line of
reasoning
...

0 marks
No response or no response worthy of credit
...
1
ALLOW any valid reason for carrying out a lifecycle assessment

Any one from:
Idea about the use of (raw) materials or energy



ALLOW idea reducing impact of raw material and
energy on environment
e
...
,
use of mining to extract the ore / energy use of
extracting ore / energy use purifying ore / using up
finite resources / damaging habitats / felling trees
ALLOW ideas about assessing efficiency
ALLOW idea reducing impact of waste products
on environment
e
...
visual/noise pollution caused by mining /dust/
CO2 from burning fossil fuels for energy / CO2
causing enhanced greenhouse effect/global
warming/climate change
ALLOW ensures that as little waste as possible is
created

Idea about environmental impact (of waste products or

using product or pollution)



Idea about lifespan of the product



Idea about disposal / recycling of the product
Ideas about sustainability



ALLOW idea about recycling being better than
using raw materials / recycling reduces landfill



ALLOW leaving resources for future generations

ALLOW Idea of product being viable
IGNORE cost

19

J250/04
Question
(b)

Mark Scheme

June 2024

AO
Marks element Guidance

Answer
Any two from:

2

2 x 1
...
g
...
2

100



= 1350



to 2 sig figs = 1400

(d)

1
...
2

ECF from M2 provided calculation shown

J250/04

Mark Scheme

QuestionAnswer
(e)

Marks

June 2024
AO
element Guidance

(i) There was an issue with this question and affected candidates’ ability to answer it
...


Aluminium oxide / Al2O3 loses oxygen
1
3
...

The electrolysis produces impure
aluminium
...


2

2 x 1
...
2

False

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






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

21

ALLOW aluminium is higher in the reactivity series
(than carbon)
IGNORE unless a comparison of reactivity is given
DO NOT ALLOW aluminium oxide/it/oxygen is
more reactive than carbon
IGNORE aluminium is very reactive

J250/04

Mark Scheme

Appendix for Level of Response, Q15
Amplification of indicative material
Graphical comments
• Steeper curve / gradient for experiment 1
• Comparison of amounts of CO2 at a given time / CO2 given off more quickly for experiment 1
IGNORE more CO2 given off unqualified by time
• Reaction finishes earlier for experiment 1 / comparison of times for levelling off
Conditions for greater rate
• Higher T
• Higher concentration / more acid particles IGNORE more acid unqualified
• Smaller pieces of marble / higher surface area IGNORE more marble chips
• Catalyst / lower activation energy
Explanations of why the conditions result in a greater rate
• More collisions (condoned for L1 and L2) IGNORE faster collisions / slower collisions
• More frequent collisions
• More successful collisions
• Smaller pieces of marble have larger surface area
• Catalyst lowers AE
• Higher temperature particles have more KE / move faster

22

June 2024

J250/04

Mark Scheme

June 2024

Amplification of level descriptors
Level 1
Experiment 1 or 2 has greater rate
• If experiment 1 is chosen / no choice, comments can be graphical or conditions or explanations
...

Level 2
Experiment 1 or 2 has greater rate
•
•

If experiment 1 is chosen, answers need to address at least 2 from graphical / explanation / conditions to ensure they have matched
their response to the AOs being assessed to meet Level 2 criteria
...


Level 3
Experiment 1 has greater rate
•

Experiment 1 is chosen AND comments must include graphical and conditions and the explanation and these must be linked
...


To achieve Level 3: Ideas of Collisions must be more frequent / more successful collisions not just more collisions must be seen

23



---