AQA A Level June 2025 Chemistry 7405/2
Paper 2 QP
Section 1: Physical Chemistry (Thermodynamics, Kinetics, Kp,
etc.)
1. What is the definition of standard enthalpy of formation?
A) The enthalpy change when one mole of a substance is
completely burned in oxygen.
B) The enthalpy change when one mole of a substance is
formed from its elements in their standard states.
C) The enthalpy change when one mole of a gaseous atom is
formed.
D) The enthalpy change when one mole of ions is dissolved in
water.
Answer: B
2. Which process is always exothermic?
A) Sublimation
B) Dissolution
C) Neutralisation
D) Vaporisation
Answer: C
3. What are the correct units for the rate constant, k, for a
reaction with the rate equation: rate = k[A]?
A) mol dm⁻³ s⁻¹
,B) s⁻¹
C) dm³ mol⁻¹ s⁻¹
D) dm⁶ mol⁻² s⁻¹
Answer: B
4. For a reaction with the rate equation rate = k[A]²[B], what is
the overall order of the reaction?
A) 1
B) 2
C) 3
D) 4
Answer: C
5. What is the role of a heterogeneous catalyst?
A) It provides an alternative reaction pathway with a lower
activation energy.
B) It increases the temperature of the reaction.
C) It increases the concentration of the reactants.
D) It changes the enthalpy change of the reaction.
Answer: A
6. In the Maxwell-Boltzmann distribution curve, what does the
area under the curve represent?
A) The total number of molecules with the most probable
energy.
B) The total energy of the system.
C) The total number of molecules.
,D) The average kinetic energy of the molecules.
Answer: C
7. What is the expression for Kc for the reaction: N₂(g) + 3H₂(g)
⇌ 2NH₃(g)?
A) [NH₃] / [N₂][H₂]
B) [NH₃]² / [N₂][H₂]³
C) [N₂][H₂]³ / [NH₃]²
D) [NH₃] / [N₂] + [H₂]
Answer: B
8. For an endothermic reaction, what happens to the value of
Kc when the temperature is increased?
A) It decreases.
B) It increases.
C) It remains the same.
D) It becomes zero.
Answer: B
9. What is the relationship between ΔG, ΔH, and ΔS?
A) ΔG = ΔH - TΔS
B) ΔG = ΔH + TΔS
C) ΔG = TΔS - ΔH
D) ΔG = ΔH / TΔS
Answer: A
, 10. A reaction is spontaneous when:
A) ΔG > 0
B) ΔG < 0
C) ΔG = 0
D) ΔH > 0
Answer: B
11. What is the definition of the standard electrode potential?
A) The e.m.f of a cell when the temperature is 298K.
B) The e.m.f of a half-cell compared to a standard hydrogen
half-cell under standard conditions.
C) The potential difference across an electrode.
D) The e.m.f of a cell when the concentration is 1 mol dm⁻³.
Answer: B
12. In an electrochemical cell, oxidation occurs at the:
A) Cathode
B) Anode
C) Salt bridge
D) Voltmeter
Answer: B
13. What is the purpose of a salt bridge?
A) To measure the current.
B) To allow the flow of electrons.
C) To complete the circuit and allow ion flow.
Paper 2 QP
Section 1: Physical Chemistry (Thermodynamics, Kinetics, Kp,
etc.)
1. What is the definition of standard enthalpy of formation?
A) The enthalpy change when one mole of a substance is
completely burned in oxygen.
B) The enthalpy change when one mole of a substance is
formed from its elements in their standard states.
C) The enthalpy change when one mole of a gaseous atom is
formed.
D) The enthalpy change when one mole of ions is dissolved in
water.
Answer: B
2. Which process is always exothermic?
A) Sublimation
B) Dissolution
C) Neutralisation
D) Vaporisation
Answer: C
3. What are the correct units for the rate constant, k, for a
reaction with the rate equation: rate = k[A]?
A) mol dm⁻³ s⁻¹
,B) s⁻¹
C) dm³ mol⁻¹ s⁻¹
D) dm⁶ mol⁻² s⁻¹
Answer: B
4. For a reaction with the rate equation rate = k[A]²[B], what is
the overall order of the reaction?
A) 1
B) 2
C) 3
D) 4
Answer: C
5. What is the role of a heterogeneous catalyst?
A) It provides an alternative reaction pathway with a lower
activation energy.
B) It increases the temperature of the reaction.
C) It increases the concentration of the reactants.
D) It changes the enthalpy change of the reaction.
Answer: A
6. In the Maxwell-Boltzmann distribution curve, what does the
area under the curve represent?
A) The total number of molecules with the most probable
energy.
B) The total energy of the system.
C) The total number of molecules.
,D) The average kinetic energy of the molecules.
Answer: C
7. What is the expression for Kc for the reaction: N₂(g) + 3H₂(g)
⇌ 2NH₃(g)?
A) [NH₃] / [N₂][H₂]
B) [NH₃]² / [N₂][H₂]³
C) [N₂][H₂]³ / [NH₃]²
D) [NH₃] / [N₂] + [H₂]
Answer: B
8. For an endothermic reaction, what happens to the value of
Kc when the temperature is increased?
A) It decreases.
B) It increases.
C) It remains the same.
D) It becomes zero.
Answer: B
9. What is the relationship between ΔG, ΔH, and ΔS?
A) ΔG = ΔH - TΔS
B) ΔG = ΔH + TΔS
C) ΔG = TΔS - ΔH
D) ΔG = ΔH / TΔS
Answer: A
, 10. A reaction is spontaneous when:
A) ΔG > 0
B) ΔG < 0
C) ΔG = 0
D) ΔH > 0
Answer: B
11. What is the definition of the standard electrode potential?
A) The e.m.f of a cell when the temperature is 298K.
B) The e.m.f of a half-cell compared to a standard hydrogen
half-cell under standard conditions.
C) The potential difference across an electrode.
D) The e.m.f of a cell when the concentration is 1 mol dm⁻³.
Answer: B
12. In an electrochemical cell, oxidation occurs at the:
A) Cathode
B) Anode
C) Salt bridge
D) Voltmeter
Answer: B
13. What is the purpose of a salt bridge?
A) To measure the current.
B) To allow the flow of electrons.
C) To complete the circuit and allow ion flow.
