Practical questions

You will complete 12 required Specified Practical Activities if you are studying GCSE Chemistry, and 27 if you are studying GCSE Combined Science (nine of these are in Chemistry). These help you develop some key practical techniques in Chemistry.

You could be asked questions about the apparatus, methods, safety precautions, results, analysis and evaluation of these experiments.

There are two Specified Practical Activities in the 'Reactivity series and extraction of metals' section:

  • determination of relative reactivities of metals through displacement reactions
  • investigation into electrolysis of aqueous solutions and electroplating

Questions courtesy of Eduqas.

Sample question 1 - Foundation

Question

Some pupils were asked to investigate what happens when a piece of shiny magnesium ribbon is added to copper(II) sulfate solution. They placed a piece of magnesium ribbon in a beaker of copper(II) sulfate and sealed the beaker. The mass was recorded at the start as 80.6 g. The mass was recorded again after one hour.

a) Choose from the grid the mass of the beaker and its contents after one hour. [1 mark]

AMore than 80.6 g
BEqual to 80.6 g
CLess than 80.6 g

b) Give the reason for your choice. [1 mark]

a)

AMore than 80.6 g
BEqual to 80.6 g
CLess than 80.6 g

b) The reaction is sealed, so nothing can enter or leave the reaction mixture. [1]

Sample question 2 - Foundation

Question

The reaction of chlorine with iron can be demonstrated by passing chlorine over iron wool in a tube. The tube has an open end to allow unreacted chlorine to escape. The iron wool is heated as the chlorine is passed over it.

State why this reaction should be carried out in a fume cupboard. [1 mark]

Chlorine is toxic [1]

Sample question 3 - Higher

Question

Describe and explain one method used to obtain copper metal from aqueous copper(II) sulfate. Include a balanced symbol equation in your answer. [4 marks]

  • add iron to copper(II) sulfate. [1]
  • iron is a more reactive metal than copper. [1]
  • iron displaces copper/iron reduces copper(II) ions. [1]
  • CuSO4 + Fe → FeSO4 + Cu [1]

Sample question 4 - Higher

Question

Three groups of students investigated how the electric current passing through a sodium chloride solution depends on the concentration of the solution.

The test was carried out using 50 cm3 of each solution. The students were given a stock solution of concentration 0.5 mol/dm3 and asked to dilute this as required to make the other solutions.

ConcentrationGroup A currentGroup B currentGroup C current
0.1 mol/dm30.07 A0.06 A0.06 A
0.2 mol/dm30.14 A0.12 A0.13 A
0.3 mol/dm30.20 A0.19 A0.20 A
0.4 mol/dm30.28 A0.26 A0.27 A
0.5 mol/dm30.35 A0.33 A0.34 A

a) Using the information in the table, describe the relationship between the concentration of sodium chloride solution and the current. [1 mark]

b) Using the information in the table, state whether the evidence to support your answer in a) is strong or weak. Explain your answer. [1 mark]

a) Any of the following for one mark:

  • the higher the concentration of sodium chloride, the higher the current
  • doubling the concentration doubles the current
  • current is proportional to concentration

[1]

b) Evidence is strong because results are reproducible/each group has similar results/each 0.1 mol/dm3 increase in concentration leads to a similar increase in current. [1]