2025 OCR A Level Chemistry B (Salters) H433/01 Fundamentals of Chemistry Combined Question
Paper & Final Marking Scheme
Oxford Cambridge and RSA
Tuesday 10 June 2025 – Morning
A Level Chemistry B (Salters)
H433/01 Fundamentals of Chemistry
Time allowed: 2 hours 15 minutes
*1849471323*
You must have:
• the Data Sheet for Chemistry B
You can use:
• a scientific or graphical calculator
• an HB pencil
* H 4 3 3 0 1 *
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined page at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 110.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 28 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/5371/4] OCR is an exempt Charity
DC (PQ/CB) 346688/5 Turn over
, 2
Section A
You should spend a maximum of 40 minutes on this section.
Write your answer to each question in the box provided.
1 Part of a protein structure can be represented as:
–CONHCH(CH3)CONHCH2CONHCH(CH3)–
What is correct about this part of the protein structure?
A All its amino acids show optical isomerism.
B It has three peptide links.
C It is an addition polymer.
D It is made from three different amino acids.
Your answer [1]
2 What is correct about the greenhouse effect?
A Greenhouse gas bonds vibrate more when warmed by infrared radiation.
B Greenhouse gases reflect infrared radiation back to Earth.
C The Earth emits mostly ultraviolet radiation.
D The principal radiation from the Sun is infrared.
Your answer [1]
3 An organic compound A is oxidised to a different compound which forms a silver mirror with Tollens’
reagent.
Which could be compound A?
A propanal
B propan-1-ol
C propan-2-ol
D propanone
Your answer [1]
© OCR 2025
, 3
4 Which statement about transition metals is correct?
A Copper(II) ions form an octahedral complex with chloride ions.
B Most manganese compounds have Mn in the oxidation state of +2, +4 or +7.
C Nickel is used as a catalyst in the hydration of alkenes.
D The dichromate ion is often used as a reducing agent.
Your answer [1]
5 Which statement about the element astatine, At, is likely to be correct?
A It displaces iodine from sodium iodide.
B It is a gas at room temperature.
C It is a weaker oxidising agent than chlorine.
D It is colourless.
Your answer [1]
6 Which of the following pairs can be structural isomers?
A acid anhydrides and aldehydes
B amines and amides
C carboxylic acids and esters
D diols and esters
Your answer [1]
7 Which row shows the correct electron configurations of Cr and Cr3+?
Cr Cr3+
A [Ar] 3d4 4s2 [Ar] 3d3
B [Ar] 3d4 4s2 [Ar] 3d1 4s2
C [Ar] 3d5 4s1 [Ar] 3d3
D [Ar] 3d5 4s1 [Ar] 3d1 4s2
Your answer [1]
© OCR 2025 Turn over
, 4
8 What is an advantage of both ethanol and hydrogen as alternatives to petrol?
A Their only product of combustion is water.
B They can be produced by fermentation.
C They do not produce nitrogen oxides in the engine.
D They do not produce oxides of sulfur on combustion.
Your answer [1]
9 What is correct about chlorine radicals in the atmosphere?
A They act as homogeneous catalysts that increase ozone depletion.
B They are formed by heterolytic fission of CFCs.
C They are formed by homolytic fission of CFCs by infrared radiation.
D They are heterogeneous catalysts that increase the rate of ozone formation.
Your answer [1]
10 A colorimeter is used to measure the concentration of a copper(II) sulfate solution.
What is correct?
A A blue filter is used.
B A calibration curve of copper ion concentration against time is used.
C The absorption increases as the concentration of copper ions increases.
D The transmission decreases as the concentration of copper ions decreases.
Your answer [1]
11 Which statement about all sodium compounds is correct?
A They are less reactive than potassium compounds.
B They dissolve in water to give alkaline solutions.
C They form giant structures.
D They give a red flame test.
Your answer [1]
© OCR 2025
Paper & Final Marking Scheme
Oxford Cambridge and RSA
Tuesday 10 June 2025 – Morning
A Level Chemistry B (Salters)
H433/01 Fundamentals of Chemistry
Time allowed: 2 hours 15 minutes
*1849471323*
You must have:
• the Data Sheet for Chemistry B
You can use:
• a scientific or graphical calculator
• an HB pencil
* H 4 3 3 0 1 *
Please write clearly in black ink. Do not write in the barcodes.
Centre number Candidate number
First name(s)
Last name
INSTRUCTIONS
• Use black ink. You can use an HB pencil, but only for graphs and diagrams.
• Write your answer to each question in the space provided. If you need extra space use
the lined page at the end of this booklet. The question numbers must be clearly shown.
• Answer all the questions.
• Where appropriate, your answer should be supported with working. Marks might be
given for using a correct method, even if your answer is wrong.
INFORMATION
• The total mark for this paper is 110.
• The marks for each question are shown in brackets [ ].
• Quality of extended response will be assessed in questions marked with an asterisk (*).
• This document has 28 pages.
ADVICE
• Read each question carefully before you start your answer.
© OCR 2025 [601/5371/4] OCR is an exempt Charity
DC (PQ/CB) 346688/5 Turn over
, 2
Section A
You should spend a maximum of 40 minutes on this section.
Write your answer to each question in the box provided.
1 Part of a protein structure can be represented as:
–CONHCH(CH3)CONHCH2CONHCH(CH3)–
What is correct about this part of the protein structure?
A All its amino acids show optical isomerism.
B It has three peptide links.
C It is an addition polymer.
D It is made from three different amino acids.
Your answer [1]
2 What is correct about the greenhouse effect?
A Greenhouse gas bonds vibrate more when warmed by infrared radiation.
B Greenhouse gases reflect infrared radiation back to Earth.
C The Earth emits mostly ultraviolet radiation.
D The principal radiation from the Sun is infrared.
Your answer [1]
3 An organic compound A is oxidised to a different compound which forms a silver mirror with Tollens’
reagent.
Which could be compound A?
A propanal
B propan-1-ol
C propan-2-ol
D propanone
Your answer [1]
© OCR 2025
, 3
4 Which statement about transition metals is correct?
A Copper(II) ions form an octahedral complex with chloride ions.
B Most manganese compounds have Mn in the oxidation state of +2, +4 or +7.
C Nickel is used as a catalyst in the hydration of alkenes.
D The dichromate ion is often used as a reducing agent.
Your answer [1]
5 Which statement about the element astatine, At, is likely to be correct?
A It displaces iodine from sodium iodide.
B It is a gas at room temperature.
C It is a weaker oxidising agent than chlorine.
D It is colourless.
Your answer [1]
6 Which of the following pairs can be structural isomers?
A acid anhydrides and aldehydes
B amines and amides
C carboxylic acids and esters
D diols and esters
Your answer [1]
7 Which row shows the correct electron configurations of Cr and Cr3+?
Cr Cr3+
A [Ar] 3d4 4s2 [Ar] 3d3
B [Ar] 3d4 4s2 [Ar] 3d1 4s2
C [Ar] 3d5 4s1 [Ar] 3d3
D [Ar] 3d5 4s1 [Ar] 3d1 4s2
Your answer [1]
© OCR 2025 Turn over
, 4
8 What is an advantage of both ethanol and hydrogen as alternatives to petrol?
A Their only product of combustion is water.
B They can be produced by fermentation.
C They do not produce nitrogen oxides in the engine.
D They do not produce oxides of sulfur on combustion.
Your answer [1]
9 What is correct about chlorine radicals in the atmosphere?
A They act as homogeneous catalysts that increase ozone depletion.
B They are formed by heterolytic fission of CFCs.
C They are formed by homolytic fission of CFCs by infrared radiation.
D They are heterogeneous catalysts that increase the rate of ozone formation.
Your answer [1]
10 A colorimeter is used to measure the concentration of a copper(II) sulfate solution.
What is correct?
A A blue filter is used.
B A calibration curve of copper ion concentration against time is used.
C The absorption increases as the concentration of copper ions increases.
D The transmission decreases as the concentration of copper ions decreases.
Your answer [1]
11 Which statement about all sodium compounds is correct?
A They are less reactive than potassium compounds.
B They dissolve in water to give alkaline solutions.
C They form giant structures.
D They give a red flame test.
Your answer [1]
© OCR 2025
