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.
[2 marks]
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 marksHigher5.1.2.5 Group 1
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.1.2.5
Original practice question
Answer and supported method checks
Three repeated demonstrations with equal samples of a group 1 metal collect hydrogen volumes of 47, 49 and 48 cm³. A separate run collects 31 cm³ after the gas tube becomes loose.
.1
Calculate the mean volume from the three valid repeated demonstrations.
[3 marks]
.2
Explain why the low run cannot show that the metal was less reactive.
[2 marks]
5 marksHigher5.4.3.4 Electrolysis of aqueous solutions5.4.3.2 Electrolysis of molten ionic compounds
AQA Trilogy 8464
Spec and skills
Paper scope: C1
Spec 5.4.3.4
Spec 5.4.3.2
Original practice question
Answer and supported method checks
A student electrolyses concentrated aqueous potassium chloride using inert electrodes in a teacher-controlled demonstration with suitable ventilation. Potassium is more reactive than hydrogen.
.1
Predict the electrode products and explain the difference from molten potassium chloride.
[3 marks]
.2
Explain how charge is carried through the aqueous electrolyte and through the external metal wires.
