From Mock A · Paper 1: Inorganic and Physical Chemistry
3.14 marks
Use the data to calculate the enthalpy of lattice formation of sodium chloride.
Enthalpy change
ΔH / kJ mol⁻¹
Formation of NaCl(s)
−411
Atomisation of Na
+107
First ionisation energy of Na
+496
Atomisation of chlorine (½Cl₂ → Cl)
+122
First electron affinity of Cl
−349
From Mock A · Paper 1: Inorganic and Physical Chemistry
3.22 marks
The value calculated from the perfect ionic model is less exothermic than the Born–Haber value for silver chloride, but almost the same for sodium chloride. Explain why.
From Mock A · Paper 1: Inorganic and Physical Chemistry
3.33 marks
For the decomposition of a carbonate, ΔH = +117 kJ mol⁻¹ and ΔS = +175 J K⁻¹ mol⁻¹. Calculate the minimum temperature at which the reaction is feasible.
From Mock A · Paper 1: Inorganic and Physical Chemistry
3.43 marks
Explain why the entropy change for this decomposition is positive.
From Mock A · Paper 3: Practical skills, all content and multiple choice
5.35 marks
Explain the trend in melting points across Period 3 from sodium to argon, linking each to structure and bonding.
From Mock A · Paper 3: Practical skills, all content and multiple choice
131 mark
A reaction has ΔH < 0 and ΔS < 0. When is it feasible?
From Mock B · Paper 1: Inorganic and Physical Chemistry
8.13 marks
For CaCO₃ → CaO + CO₂, ΔH = +178 kJ mol⁻¹ and ΔS = +161 J K⁻¹ mol⁻¹. Calculate the minimum temperature at which the reaction is feasible.
From Mock B · Paper 1: Inorganic and Physical Chemistry
8.22 marks
Explain why the entropy change for this reaction is positive.
From Mock B · Paper 3: Practical skills, all content and multiple choice
65 marks
For the Haber process, N₂ + 3H₂ ⇌ 2NH₃, ΔH = −92 kJ mol⁻¹. Explain why the industrial conditions are 450 °C and 200 atm with an iron catalyst, referring to yield, rate and cost.
From Mock B · Paper 3: Practical skills, all content and multiple choice
181 mark
Which process has a negative entropy change?
From Mock C · Paper 1: Inorganic and Physical Chemistry
8.14 marks
Use the data to calculate the enthalpy of solution of MgCl₂ (data are illustrative, written for this paper): lattice enthalpy of dissociation +2526 kJ mol⁻¹; hydration enthalpy Mg²⁺ −1920, Cl⁻ −364 kJ mol⁻¹. Explain whether it dissolves exothermically.
From Mock C · Paper 1: Inorganic and Physical Chemistry
8.23 marks
Explain why a reaction with positive ΔH and positive ΔS becomes feasible at high temperature.
From Mock C · Paper 1: Inorganic and Physical Chemistry
176 marks
Methanol is made industrially: CO(g) + 2H₂(g) ⇌ CH₃OH(g), ΔH = −91 kJ mol⁻¹. Discuss the choice of temperature, pressure and catalyst, referring to yield, rate, feasibility and cost.
From Mock C · Paper 3: Practical skills, all content and multiple choice
95 marks
Explain why the enthalpy of lattice formation of MgO is much more exothermic than that of NaCl, and why experimental and perfect ionic model values can differ.
From Mock C · Paper 3: Practical skills, all content and multiple choice
171 mark
A reaction is feasible when
Score 0 / 48 · 0 of 15 marked
This paper is written by Plasmo in the style of the AQA A-Level Chemistry exam. It is not a past paper and is not produced or endorsed by the exam board.