6 marksHigherRequired practical 085.4.2.2 Neutralisation of acids and salt production5.4.2.3 Soluble salts
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.4.2.2
Spec 5.4.2.3
Original practice question
Answer and supported method checks
Dilute hydrochloric acid is added to excess copper oxide. The black oxide becomes a blue-green copper chloride solution, with black solid remaining.
.1
Write the balanced equation.
[2 marks]
.2
Explain why excess copper oxide is used and how it is removed.
[2 marks]
.3
Explain why the mass of wet crystals would overestimate the mass of salt recovered.
[2 marks]
5 marksFoundation and Higher5.2.1.4 Covalent bonding
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.2.1.4
Original practice question
Answer and supported method checks
An oxygen molecule contains two oxygen atoms. Each atom has six outer electrons.
.1
Explain the bonding needed for both atoms to achieve full outer shells.
[3 marks]
.2
Explain why a line drawing O=O does not show every electron.
[2 marks]
4 marksHigher5.5.1.3 The energy change of reactions
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.5.1.3
Original practice question
Answer and supported method checks
A pupil estimates the energy change for CH4+Cl2→CH3Cl+HCl. Bond energies are C-H 413, Cl-Cl 243, C-Cl 338 and H-Cl 431 kJ/mol.
.1
Calculate the energy change using only bonds that change.
[3 marks]
.2
Evaluate the claim that breaking the C-H bond supplies the energy released.
[1 mark]
4 marksFoundation and Higher5.2.2.5 Polymers
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.2.2.5
Original practice question
Answer and supported method checks
A polymer model contains 150 chains. Each chain contains 400 repeat units.
.1
Calculate the total number of repeat units represented.
[2 marks]
.2
Explain why this model represents a polymer rather than a giant covalent lattice.
[2 marks]
6 marksFoundation and Higher5.4.3.3 Using electrolysis to extract metals
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.4.3.3
Original practice question
Answer and supported method checks
A factory uses electrolysis to extract aluminium. One operating mixture needs 1200 energy units per batch; adding cryolite reduces the requirement to 900 units per equal batch.
.1
Calculate the percentage reduction in energy use.
[3 marks]
.2
Explain how cryolite reduces energy use and why the positive electrodes need replacement.
