Practical questions

You will complete 21 required practical activities if you are studying GCSE combined science: Synergy. You could be asked questions about the apparatus, methods, safety precautions, results, analysis and evaluation of these experiments.

There will be a number of different types of practical based questions. Some will be on the set required practicals, some will cover the working scientifically terms and some will be on other science practicals which you might have done in class. Use all the information given in the question particularly any diagrams to help you understand what the question is about.

This page contains AQA material which is reproduced by permission of AQA.

Sample question 1 - Foundation

Question

A student reacted four metals with water and with dilute acid to work out the order of reactivity of the metals.

The table shows some of the observations.

MetalReaction with waterReaction with dilute acid
CalciumBubbles of gasX
CopperYNo bubbles of gas
MagnesiumFew bubbles of gasBubbles of gas
ZincNo bubbles of gasBubbles of gas

Write down the observations for X and Y. [2 marks]

X bubbles of gas [1].

Y no bubbles of gas [1].

Sample question 2 - Foundation

Question

A student investigates how the concentration of an acid affects the rate of a reaction.

This is the method used.

  1. Put a 3 cm piece of magnesium ribbon into a conical flask.
  2. Add 50 cm3 of 0.5 mol/dm3 hydrochloric acid into the flask.
  3. Collect and measure the volume of gas produced at 10 second intervals.
  4. Repeat with different concentrations of hydrochloric acid using the same length of magnesium ribbon and volume of acid.

The student's results are shown in the graph below: .

Total volume of gas collected verses time graph

How do the results show that increasing the concentration of acid increases the rate of reaction?

You must use data from the graph in your answer. [2 marks]

As the concentration increases:

  • the relationship is identified from the graph [1]
    • example: the same volume of gas is collected in a shorter time or more gas is collected in the same time or reaction reaches completion in a shorter time
  • reference to relevant data to evidence relationship [1]
    • example: 20 cm3 collected in 10 seconds at 0.5 mol/dm3 in 6.5 s at 1.0 mol/dm3 and in 4 seconds at 2.0 mol/dm3
    • example: at 10 seconds volume collected is 20 cm3 with 1.0 mol/dm3, 30 cm3 with 1.0 mol/dm3, 50 cm3 with 2.0 mol/dm3
    • example: total volume collected reaches maximum of 100 cm3 in 20 seconds at 2.0 mol/dm3 but takes twice as long at 1.0 cm3 and at 0.5 mol/dm3

Sample question 3 - Higher

Question

A student is investigating some electrical components.

Describe how the student could set up a circuit to find the resistance of a lamp.

You should include a circuit diagram in your answer. [4 marks]

A circuit diagram of an ammeter in series and voltmeter in parallel

If ammeter is connected in series and voltmeter in parallel [2].

Measure the potential difference across the lamp at known current [1].

Calculate resistance from measured values using V = IR [1].

Sample question 4 - Higher

Question

A student is investigating some electrical components.

The student is given an electrical component in a sealed box.

She has to find out what the electrical component is by experiment.

Her results are shown in the graph below.

A current verses potential difference graph

Explain how the student could know that the electrical component in the sealed box is not an ohmic conductor. [2 marks]

For ohmic conductors the current is directly proportional to the potential difference applied across it [1].

This graph is curved so it is not an ohmic conductor [1].