5 marksHigher5.10.1.4 Alternative methods of extracting metals
AQA Trilogy 8464
Spec and skills
Paper scope: C2
Spec 5.10.1.4
Original practice question
Answer and supported method checks
A trial compares conventional mining with bioleaching for the same mass of copper recovered. Mining causes 120 units of landscape disturbance and uses 900 units of energy; bioleaching causes 35 and uses 600. Bioleaching takes much longer and its leachate must be contained.
.1
Calculate the percentage energy saving using bioleaching compared with mining.
[2 marks]
.2
Evaluate the claim that bioleaching has no environmental disadvantages.
[3 marks]
4 marksHigher5.6.2.3 Equilibrium
AQA Trilogy 8464
Spec and skills
Paper scope: C2
Spec 5.6.2.3
Original practice question
Answer and supported method checks
A computer model displays 70 reactant particles and 30 product particles at equilibrium. During the next second 6 reactant particles change to product.
.1
Calculate the percentage of reactant particles that change to product in that second. Give your answer to at least two significant figures.
[2 marks]
.2
Predict the number changing back in the same second and explain why the display can stay at 70:30.
[2 marks]
4 marksFoundation and Higher5.9.3.1 Atmospheric pollutants from fuels
AQA Trilogy 8464
Spec and skills
Paper scope: C2
Spec 5.9.3.1
Original practice question
Answer and supported method checks
A company claims that because its hydrocarbon fuel burns with no smoke it causes neither acid rain nor climate change. The fuel contains small amounts of sulfur and is burned at high temperature in air.
Evaluate the claim using the possible gaseous products.
[4 marks]
4 marksFoundation and Higher5.6.1.1 Calculating rates of reactions
AQA Trilogy 8464
Spec and skills
Paper scope: C2
Spec 5.6.1.1
Original practice question
Answer and supported method checks
A reaction uses the same solution concentration at 20 °C and 35 °C. A student explains the faster reaction at 35 °C by saying particles are larger and the activation energy has decreased.
Evaluate the explanation.
[4 marks]
4 marksFoundation and Higher5.7.1.2 Fractional distillation and petrochemicals
AQA Trilogy 8464
Spec and skills
Paper scope: C2
Spec 5.7.1.2
Original practice question
Answer and supported method checks
A student says: "Crude oil is a compound. Fractional distillation breaks its molecules into simpler hydrocarbons. Each fraction contains one pure substance."
