4 marksFoundation and Higher5.4.2.4 The pH scale and neutralisation
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.4.2.4
Original practice question
Answer and supported method checks
A student adds an alkali gradually to an acid. The measured pH values after successive additions are 2, 4, 6, 7, 9 and 11.
.1
Describe the change and identify the neutral reading.
[2 marks]
.2
Explain neutralisation in terms of the reacting ions.
[2 marks]
5 marksHigher5.1.1.6 Relative atomic mass
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.1.1.6
Original practice question
Answer and supported method checks
An element has only isotopes X-50 and X-54. Its measured relative atomic mass is 51.2.
.1
Calculate the percentage abundance of X-54.
[3 marks]
.2
Evaluate a claim that the two isotopes are equally abundant.
[2 marks]
5 marksFoundation and Higher5.3.1.1 Conservation of mass and balanced chemical equations
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.3.1.1
Original practice question
Answer and supported method checks
Propane burns completely in oxygen to form carbon dioxide and water. A sample uses 8.0 g oxygen and produces 6.6 g carbon dioxide and 3.6 g water. No products escape before weighing.
.1
Write the balanced equation for complete combustion of propane, C3H8.
[2 marks]
.2
Calculate the mass of propane that reacted.
[3 marks]
6 marksHigher5.3.2.1 Moles
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.3.2.1
Original practice question
Answer and supported method checks
Copper oxide is reduced by hydrogen: CuO+H2→Cu+H2O. A process must produce 12.8 g copper. Ar: Cu = 64, O = 16, H = 1.
.1
Calculate the minimum mass of copper oxide needed if conversion is complete.
[4 marks]
.2
Calculate the mass of hydrogen that reacts with this copper oxide.
[2 marks]
5 marksHigher5.2.1.1 Chemical bonds5.2.1.2 Ionic bonding5.2.1.4 Covalent bonding
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.2.1.1
Spec 5.2.1.2
Spec 5.2.1.4
Original practice question
Answer and supported method checks
A bottle contains carbon dioxide molecules. A sample of magnesium chloride contains Mg2+ and Cl− ions.
.1
Compare how bonds form in the two substances.
[3 marks]
.2
Explain why one magnesium atom needs two chlorine atoms to form the compound.
