Chemical equilibria, Le Chatelier's principle and Kc
From Mock A · Paper 1: Inorganic and Physical Chemistry
4.14 marks
1.00 mol of H₂ and 1.00 mol of I₂ were heated in a 2.00 dm³ flask. At equilibrium, 1.56 mol of HI was present.
H₂(g) + I₂(g) ⇌ 2HI(g)
Calculate Kc.
From Mock A · Paper 1: Inorganic and Physical Chemistry
4.42 marks
State the effect of a catalyst on Kp and on the time taken to reach equilibrium.
From Mock A · Paper 3: Practical skills, all content and multiple choice
5.15 marks
Explain why the Haber process is run at about 450 °C and 200 atm with an iron catalyst, rather than the conditions that give the highest equilibrium yield.
From Mock A · Paper 3: Practical skills, all content and multiple choice
111 mark
For 2SO₂ + O₂ ⇌ 2SO₃ (ΔH negative), which change increases the equilibrium yield of SO₃?
From Mock B · Paper 1: Inorganic and Physical Chemistry
6.14 marks
1.00 mol H₂ and 1.00 mol I₂ were sealed in a 1.00 dm³ flask. At equilibrium, 1.56 mol HI was present. H₂ + I₂ ⇌ 2HI. Calculate Kc.
From Mock B · Paper 1: Inorganic and Physical Chemistry
6.22 marks
State and explain the effect of increasing pressure on the position of this equilibrium.
From Mock B · Paper 1: Inorganic and Physical Chemistry
6.32 marks
Explain why a catalyst does not change the value of Kc.
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
161 mark
For an exothermic equilibrium, increasing temperature will
From Mock C · Paper 1: Inorganic and Physical Chemistry
6.13 marks
Write the Kc expression for 2SO₂ + O₂ ⇌ 2SO₃ and give its units.
From Mock C · Paper 1: Inorganic and Physical Chemistry
6.23 marks
Explain the effect of increasing pressure on the yield of SO₃ and on Kc.
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 2: Organic and Physical Chemistry
15.53 marks
Use your answer to 15.4 to explain the effect of increasing temperature and pressure on the equilibrium yield of ethanol.
From Mock C · Paper 3: Practical skills, all content and multiple choice
151 mark
Adding more reactant to a system at equilibrium will
Score 0 / 42 · 0 of 14 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.
Chemical equilibria, Le Chatelier's principle and Kc Exam Questions: AQA A-Level Chemistry | Plasmo