Edexcel A-Level Chemistry Paper 1, June 2025
Every question from Edexcel A-Level Chemistry Paper 1, June 2025 (9CH0): 9 questions, 90 marks, each with its mark scheme and topic.
- Question 1 6 marks
Define relative isotopic mass and isotope using argon as an example, and calculate the relative atomic mass of argon to two decimal places.
Physical Chemistry · Topic 1: Atomic Structure and the Periodic Table
- Question 2 16 marks
Explain trends in first ionisation energies, write equations and identify orbitals/radii for elements and ions, and discuss differences in boiling temperatures based on intermolecular forces.
Physical Chemistry · Topic 1: Atomic Structure and the Periodic Table · Topic 2: Bonding and Structure
- Question 3 18 marks
Investigate the enthalpy change for the thermal decomposition of calcium carbonate using indirect calorimetry, calculate Gibbs free energy and feasibility, and explain the thermal stability trend of Group 2 carbonates.
Physical Chemistry · Inorganic Chemistry · Core Practicals · Core Practical 8: Determine the enthalpy change of a reaction using Hess’s law · Topic 8: Energetics I · Topic 13: Energetics II · Topic 4: Inorganic Chemistry and the Periodic Table · Topic 5: Formulae, Equations and Amounts of Substance
- Question 4 8 marks
Calculate the equilibrium constant Kp and its units for the industrial hydration of ethene, and explain the effects of pressure and temperature on the equilibrium and Kp.
Physical Chemistry · Topic 11: Equilibrium II · Topic 10: Equilibrium I
- Question 5 3 marks
Identify a conjugate acid-base pair, state the mathematical definition of pH, and calculate the hydroxide ion concentration of a solution given its pH.
Physical Chemistry · Topic 12: Acid-base Equilibria
- Question 6 19 marks
Analyse the chemistry of chromium, including electronic configurations, complex ion shapes and colours, amphoteric reactions, ligand exchange, and redox feasibility calculations.
Inorganic Chemistry · Physical Chemistry · Topic 15: Transition Metals · Topic 1: Atomic Structure and the Periodic Table · Topic 14: Redox II
- Question 7 3 marks
Identify the definition of lattice energy, the compound with the most exothermic lattice energy, and the compound with the greatest difference between theoretical and experimental lattice energies.
Physical Chemistry · Topic 13: Energetics II · Topic 2: Bonding and Structure
- Question 8 6 marks
Compare and contrast the mechanisms of heterogeneous vanadium(V) oxide and homogeneous iron(II) catalysts, illustrating with equations for the redox reactions involved.
Inorganic Chemistry · Physical Chemistry · Topic 15: Transition Metals · Topic 9: Kinetics I · Topic 3: Redox I
- Question 9 11 marks
Analyse titration data for the reaction between acidified potassium manganate(VII) and hydrogen peroxide in hand sanitiser to determine mass percentage and experimental uncertainties.
Physical Chemistry · Topic 3: Redox I · Topic 5: Formulae, Equations and Amounts of Substance