Practical questions

You will complete 21 required practical activities if you are studying GCSE combined science: Trilogy. 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.

There is one required practical activity in the Energy changes section:

  • Investigate the variable that affect temperature changes in reacting solutions such as acid plus metals, acid plus carbonates, neutralisations, displacement of metals.

These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.

Sample question 1 - Foundation

Question

A student wants to answer the scientific question below:

When magnesium is added to dilute hydrochloric acid, how does acid concentration affect temperature change?

Tick one box in each row of Table 1 to identify the different types of variable in the investigation. [3 marks]

Table 1

Variable✔ if this is the independent variable✔ if this is the dependent variable✔ if this is the control variable
Acid concentration
Volume of Acid
Temperature change
Mass of Magnesium
Variable✔ if this is the independent variable✔ if this is the dependent variable✔ if this is the control variable
Acid concentration
Volume of Acid
Temperature change
Mass of Magnesium

Sample question 2 - Higher

Question

A student investigates the reaction of calcium carbonate with dilute hydrochloric acid.

She wants to find out the effect of acid concentration on temperature change.

This is the method used.

  1. Pour acid into a beaker so that the beaker is about half full.
  2. Measure the temperature of the acid.
  3. Add some calcium carbonate.
  4. As soon as the reacting mixture stops bubbling, measure the temperature.
  5. Repeat with acid solutions of different concentrations.

a) Suggest and explain an improvement to step 1. [2 marks]

b) Name the measuring instrument used in step 2. [1 mark]

c) In step 3, explain why the student must measure the temperature as soon as the mixture stops bubbling, and not wait until later. [1 mark]

a) Use a measuring cylinder so that the same known volume of acid can be used for each concentration [1] so that the investigation is a fair test. [1]

b) Thermometer [1]

c) If the student waits energy will be transferred to the surroundings so the temperature will decrease. [1]

Sample question 3 - Higher

Question

A student investigates the reaction of magnesium with dilute hydrochloric acid.

She measures the temperature change when she adds magnesium to hydrochloric acid solutions of three different concentrations. She makes three measurements at each concentration.

Her results are in Table 2.

Table 2

Relative concentrationTemperature change (°C)
Run 1Run 2Run 3
0.2+1+3+2
0.4+6+5+6
0.6+10+12+8

Write down the concentration for which the measurements are most precise.

Explain your answer. [2 marks]

0.4 [1] because the three measurements are most closely clustered at this relative concentration [1].