A LEVEL CHEMISTRY B (SALTERS): Actual June 2025 PAST PAPER 1:
Fundamentals of Chemistry. All Assessment Questions & Mark Scheme [OCR
H433/01]
Exam Resource Summary
The A Level Chemistry B (Salters) June 2025 Paper 1: Fundamentals of Chemistry (OCR
H433/01) – All Assessment Questions & Mark Scheme merges the complete official examination
paper with its comprehensive mark scheme, providing an invaluable resource for effective exam
preparation. This paper assesses students’ understanding of the core principles that underpin
chemistry, including atomic structure, bonding, periodicity, energetics, kinetics, equilibria,
redox processes, and the foundations of organic chemistry. It tests both theoretical knowledge
and the ability to apply chemical concepts to novel and practical situations, requiring precision,
analytical reasoning, and problem-solving skills. The merged format presents each question
alongside its marking criteria, offering clear visibility into examiner expectations, mark
distribution, and structured response techniques. This resource is essential for targeted
revision, self-assessment, and the consolidation of key chemical concepts, ensuring confident
preparation for the June 2025 OCR A Level Chemistry B (Salters) Paper 1 and providing a
strong foundation for advanced scientific learning and application.
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
Fundamentals of Chemistry. All Assessment Questions & Mark Scheme [OCR
H433/01]
Exam Resource Summary
The A Level Chemistry B (Salters) June 2025 Paper 1: Fundamentals of Chemistry (OCR
H433/01) – All Assessment Questions & Mark Scheme merges the complete official examination
paper with its comprehensive mark scheme, providing an invaluable resource for effective exam
preparation. This paper assesses students’ understanding of the core principles that underpin
chemistry, including atomic structure, bonding, periodicity, energetics, kinetics, equilibria,
redox processes, and the foundations of organic chemistry. It tests both theoretical knowledge
and the ability to apply chemical concepts to novel and practical situations, requiring precision,
analytical reasoning, and problem-solving skills. The merged format presents each question
alongside its marking criteria, offering clear visibility into examiner expectations, mark
distribution, and structured response techniques. This resource is essential for targeted
revision, self-assessment, and the consolidation of key chemical concepts, ensuring confident
preparation for the June 2025 OCR A Level Chemistry B (Salters) Paper 1 and providing a
strong foundation for advanced scientific learning and application.
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
