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 Using resources section:
- Investigate the variable that affect temperature changes in reacting solutions such as acid plus metals, acid plus carbonates, neutralisations, displacement of metals.
Sample question 1 - Foundation
Question
Complete the diagram to show how you can distil salt solution to produce and collect pure water.
Label the following:
- Pure water
- Salt solution
[3 marks]
This question is AQA material which is reproduced by permission of AQA.
Salt solution in conical flask or round bottomed flask connected to bung on diagram [1]
Pure water in test tube or beaker at the end of the glass tube on the right (must not be sealed to the glass tube) [1]
Heat source below conical or round bottomed flask [1]
Sample question 2 - Foundation
Question
A student analysed water samples from natural sources.
His results are in the table.
| Water source | pH of water sample | Total mass of dissolved solids in 100 g of water, in g |
| X | 7.9 | 0.13 |
| Y | 8.1 | 3.50 |
| Z | 7.1 | 0.00 |
| Water source | X |
|---|---|
| pH of water sample | 7.9 |
| Total mass of dissolved solids in 100 g of water, in g | 0.13 |
| Water source | Y |
|---|---|
| pH of water sample | 8.1 |
| Total mass of dissolved solids in 100 g of water, in g | 3.50 |
| Water source | Z |
|---|---|
| pH of water sample | 7.1 |
| Total mass of dissolved solids in 100 g of water, in g | 0.00 |
a) Which water sample is most alkaline? [1 mark]
b) Which water sample is pure? [1 mark]
c) Which water sample might have come from the sea? Give a reason for your decision. [2 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
a) Y [1]
b) Z [1]
c) Y [1] because it contains the greatest amount of dissolved solids [1]
Sample question 3 - Higher
Question
Some students are purifying water in the school laboratory. They follow this procedure.
- Fold a circular piece of filter paper in half and then in half again. Open up the curved edge to form a cone of paper.
- Poke a small hole into the corner of the filter paper cone and then place into a plastic filter funnel.
- Place the filter funnel into a conical flask, then pour the water to be purified into the filter paper.
Identify the error in the students' method and explain the consequence of their mistake. [2 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
- Poking a hole through the filter paper [1]
- This will allow insoluble particles to pass into the filtrate [1]
Sample question 4 - Higher
Question
A student did an experiment on phytomining. He planted some seeds and, when they had started to grow, placed their roots in a container of copper sulfate solution. The volume of solution was 5 dm3. He left the plants to grow for 14 days.
The student collected the data in the table.
| Day | Concentration of copper sulfate solution in mg/dm3 |
| 1 | 30 |
| 14 | 10 |
| Day | 1 |
|---|---|
| Concentration of copper sulfate solution in mg/dm3 | 30 |
| Day | 14 |
|---|---|
| Concentration of copper sulfate solution in mg/dm3 | 10 |
Use the results to calculate the mass of copper sulfate that was absorbed by the plants. [3 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
Mass of copper sulfate at start = concentration × volume of solution
= 30 mg/dm3 × 5 dm3
= 150 mg [1]
Mass of copper sulfate at end = concentration × volume of solution
= 10 mg/dm3 × 5 dm3
= 50 mg [1]
Mass of copper sulfate absorbed by plants = 150 mg - 50 mg
= 100 mg [1]