General Certificate of Secondary Education
2025
Chemistry
Unit 2
Foundation Tier
[GCM21]
FRIDAY 13 JUNE, MORNING
MARK
SCHEME
14543.01 F
,General Marking Instructions
Introduction
Mark schemes are intended to ensure that the GCSE examinations are marked consistently and fairly.
The mark schemes provide markers with an indication of the nature and range of candidates’ responses
likely to be worthy of credit. They also set out the criteria which they should apply in allocating marks to
candidates’ responses.
Assessment objectives
Below are the assessment objectives for GCSE Chemistry.
Candidates must:
AO1 Demonstrate knowledge and understanding of:
– scientific ideas;
– scientific techniques and procedures.
AO2 Apply knowledge and understanding of and develop skills in:
– scientific ideas;
– scientific enquiry, techniques and procedures.
AO3 Analyse scientific information and ideas to:
– interpret and evaluate;
– make judgements and draw conclusions;
– develop and improve experimental procedures.
Quality of candidates’ responses
In marking the examination papers, examiners should be looking for a quality of response reflecting
the level of maturity which may reasonably be expected of a 16-year-old which is the age at which the
majority of candidates sit their GCSE examinations.
Flexibility in marking
Mark schemes are not intended to be totally prescriptive. No mark scheme can cover all the responses
which candidates may produce. In the event of unanticipated answers, examiners are expected to use
their professional judgement to assess the validity of answers. If an answer is particularly problematic,
then examiners should seek the guidance of the Supervising Examiner.
Positive marking
Examiners are encouraged to be positive in their marking, giving appropriate credit for what candidates
know, understand and can do rather than penalising candidates for errors or omissions. The exception
to this for GCSE Chemistry is when examiners are marking complex calculations when the examiners
are briefed to mark by error or omission. Examiners should make use of the whole of the available mark
range for any particular question and be prepared to award full marks for a response which is as good as
might reasonably be expected of a 16-year-old GCSE candidate.
Awarding zero marks
Marks should only be awarded for valid responses and no marks should be awarded for an answer
which is completely incorrect or inappropriate.
Marking calculations
In marking answers involving calculations, examiners should apply the ‘carry error through’ rule so that
candidates are not penalised more than once for a computational error. To avoid a candidate being
penalised, marks can be awarded where correct conclusions or inferences are made from their incorrect
calculations.
14543.01 F 2
,Types of mark schemes
Mark schemes for tasks or questions which require candidates to respond in extended written form are
marked on the basis of levels of response which take account of the quality of written communication.
Other questions which require only short answers are marked on a point for point basis with marks
awarded for each valid piece of information provided.
Levels of response
In deciding which level of response to award, examiners should look for the number of indicative content
points in candidate responses to ensure that the answer has been written to coincide with the question.
In deciding which mark within a particular level to award to any response, quality of communication will
be assessed and examiners are expected to use their professional judgement.
The following guidance is provided to assist examiners.
Threshold performance: Response which just merits inclusion in the level and should be awarded
a mark at or near the bottom of the range.
High performance: Response which fully satisfies the level description and should be awarded a
mark at or near the top of the range.
Quality of written communication
Quality of written communication is taken into account in assessing candidates’ responses to all tasks
and questions that require them to respond in extended written form. These tasks and questions are
marked on the basis of bands of response. The description for each band of response includes reference
to the quality of written communication.
For conciseness, quality of written communication is distinguished within bands of response as follows:
Band A: Quality of written communication is excellent.
Band B: Quality of written communication is good.
Band C: Quality of written communication is basic.
Band D: Response not worthy of credit
In interpreting these band descriptions, examiners should refer to the more detailed guidance provided
below:
Band A (Excellent): Excellent reference to scientific terminology. The candidate successfully selects and
uses the most appropriate form and style of writing. Relevant material is organised with a high degree
of clarity and coherence. There is widespread and accurate use of appropriate specialist vocabulary.
Presentation, spelling, punctuation and grammar are of a sufficiently high standard to make meaning
clear.
Band B (Good): Good reference to scientific terminology. The candidate makes a reasonable selection
and use of an appropriate form and style of writing. Relevant material is organised with some clarity and
coherence. There is some use of appropriate specialist vocabulary. Presentation, spelling, punctuation
and grammar are sufficiently competent to make meaning clear.
Band C (Basic): Basic reference to scientific terminology. The candidate makes only a limited selection
and use of an appropriate form and style of writing. The organisation of material may lack clarity and
coherence. There is little use of specialist vocabulary. Presentation, spelling, punctuation and grammar
may be such that intended meaning is not clear.
14543.01 F 3
, Where one response is required to gain a mark, candidates will not gain credit AVAILABLE
if a correct response is given alongside one or more incorrect responses. MARKS
This is referred to as listing.
1 (a) (i) gas syringe [1]
(ii) water and oxygen [1]
(iii) C as reaction is fastest/least time [1]
(iv) manganese dioxide/manganese(IV) oxide [1]
(b) (i) 20–22 cm3 [1]
(ii) (gas volume) increases [1]
at time 114–120 s (gas volume) reaches maximum/levels off [1] [2]
(c) (i) only one product [1]
(ii) economic reasons/more sustainable/no waste [1] 9
14543.01 F 4
2025
Chemistry
Unit 2
Foundation Tier
[GCM21]
FRIDAY 13 JUNE, MORNING
MARK
SCHEME
14543.01 F
,General Marking Instructions
Introduction
Mark schemes are intended to ensure that the GCSE examinations are marked consistently and fairly.
The mark schemes provide markers with an indication of the nature and range of candidates’ responses
likely to be worthy of credit. They also set out the criteria which they should apply in allocating marks to
candidates’ responses.
Assessment objectives
Below are the assessment objectives for GCSE Chemistry.
Candidates must:
AO1 Demonstrate knowledge and understanding of:
– scientific ideas;
– scientific techniques and procedures.
AO2 Apply knowledge and understanding of and develop skills in:
– scientific ideas;
– scientific enquiry, techniques and procedures.
AO3 Analyse scientific information and ideas to:
– interpret and evaluate;
– make judgements and draw conclusions;
– develop and improve experimental procedures.
Quality of candidates’ responses
In marking the examination papers, examiners should be looking for a quality of response reflecting
the level of maturity which may reasonably be expected of a 16-year-old which is the age at which the
majority of candidates sit their GCSE examinations.
Flexibility in marking
Mark schemes are not intended to be totally prescriptive. No mark scheme can cover all the responses
which candidates may produce. In the event of unanticipated answers, examiners are expected to use
their professional judgement to assess the validity of answers. If an answer is particularly problematic,
then examiners should seek the guidance of the Supervising Examiner.
Positive marking
Examiners are encouraged to be positive in their marking, giving appropriate credit for what candidates
know, understand and can do rather than penalising candidates for errors or omissions. The exception
to this for GCSE Chemistry is when examiners are marking complex calculations when the examiners
are briefed to mark by error or omission. Examiners should make use of the whole of the available mark
range for any particular question and be prepared to award full marks for a response which is as good as
might reasonably be expected of a 16-year-old GCSE candidate.
Awarding zero marks
Marks should only be awarded for valid responses and no marks should be awarded for an answer
which is completely incorrect or inappropriate.
Marking calculations
In marking answers involving calculations, examiners should apply the ‘carry error through’ rule so that
candidates are not penalised more than once for a computational error. To avoid a candidate being
penalised, marks can be awarded where correct conclusions or inferences are made from their incorrect
calculations.
14543.01 F 2
,Types of mark schemes
Mark schemes for tasks or questions which require candidates to respond in extended written form are
marked on the basis of levels of response which take account of the quality of written communication.
Other questions which require only short answers are marked on a point for point basis with marks
awarded for each valid piece of information provided.
Levels of response
In deciding which level of response to award, examiners should look for the number of indicative content
points in candidate responses to ensure that the answer has been written to coincide with the question.
In deciding which mark within a particular level to award to any response, quality of communication will
be assessed and examiners are expected to use their professional judgement.
The following guidance is provided to assist examiners.
Threshold performance: Response which just merits inclusion in the level and should be awarded
a mark at or near the bottom of the range.
High performance: Response which fully satisfies the level description and should be awarded a
mark at or near the top of the range.
Quality of written communication
Quality of written communication is taken into account in assessing candidates’ responses to all tasks
and questions that require them to respond in extended written form. These tasks and questions are
marked on the basis of bands of response. The description for each band of response includes reference
to the quality of written communication.
For conciseness, quality of written communication is distinguished within bands of response as follows:
Band A: Quality of written communication is excellent.
Band B: Quality of written communication is good.
Band C: Quality of written communication is basic.
Band D: Response not worthy of credit
In interpreting these band descriptions, examiners should refer to the more detailed guidance provided
below:
Band A (Excellent): Excellent reference to scientific terminology. The candidate successfully selects and
uses the most appropriate form and style of writing. Relevant material is organised with a high degree
of clarity and coherence. There is widespread and accurate use of appropriate specialist vocabulary.
Presentation, spelling, punctuation and grammar are of a sufficiently high standard to make meaning
clear.
Band B (Good): Good reference to scientific terminology. The candidate makes a reasonable selection
and use of an appropriate form and style of writing. Relevant material is organised with some clarity and
coherence. There is some use of appropriate specialist vocabulary. Presentation, spelling, punctuation
and grammar are sufficiently competent to make meaning clear.
Band C (Basic): Basic reference to scientific terminology. The candidate makes only a limited selection
and use of an appropriate form and style of writing. The organisation of material may lack clarity and
coherence. There is little use of specialist vocabulary. Presentation, spelling, punctuation and grammar
may be such that intended meaning is not clear.
14543.01 F 3
, Where one response is required to gain a mark, candidates will not gain credit AVAILABLE
if a correct response is given alongside one or more incorrect responses. MARKS
This is referred to as listing.
1 (a) (i) gas syringe [1]
(ii) water and oxygen [1]
(iii) C as reaction is fastest/least time [1]
(iv) manganese dioxide/manganese(IV) oxide [1]
(b) (i) 20–22 cm3 [1]
(ii) (gas volume) increases [1]
at time 114–120 s (gas volume) reaches maximum/levels off [1] [2]
(c) (i) only one product [1]
(ii) economic reasons/more sustainable/no waste [1] 9
14543.01 F 4
