Sofia and Marcus each measured 10 cm³ of dilute hydrochloric acid into a test tube and measured the temperature. Then they each added an identical piece of magnesium ribbon to their test tube of acid. When the reaction stopped, they each measured the temperature again.
| Learner | Start temperature / °C | End temperature / °C |
|---|---:|---:|
| Sofia | 18 | 42 |
| Marcus | 21 | 45 |
What are the products when magnesium and hydrochloric acid react?
Sofia and Marcus each measured 10 cm³ of dilute hydrochloric acid into a test tube and measured the temperature. Then they each added an identical piece of magnesium ribbon to their test tube of acid. When the reaction stopped, they each measured the temperature again.
| Learner | Start temperature / °C | End temperature / °C |
|---|---:|---:|
| Sofia | 18 | 42 |
| Marcus | 21 | 45 |
How did Sofia and Marcus know when the reaction had finished?
Sofia and Marcus each measured 10 cm³ of dilute hydrochloric acid into a test tube and measured the temperature. Then they each added an identical piece of magnesium ribbon to their test tube of acid. When the reaction stopped, they each measured the temperature again.
| Learner | Start temperature / °C | End temperature / °C |
|---|---:|---:|
| Sofia | 18 | 42 |
| Marcus | 21 | 45 |
Marcus thought that more chemical energy had been changed to thermal energy by his reaction because, in his experiment, the end temperature was higher. Sofia thought that both reactions changed the same quantity of chemical energy to thermal energy. Whose idea is correct? Explain why?
Sofia and Marcus each measured 10 cm³ of dilute hydrochloric acid into a test tube and measured the temperature. Then they each added an identical piece of magnesium ribbon to their test tube of acid. When the reaction stopped, they each measured the temperature again.
| Learner | Start temperature / °C | End temperature / °C |
|---|---:|---:|
| Sofia | 18 | 42 |
| Marcus | 21 | 45 |
Explain why it is a good idea to wear safety glasses whilst carrying out this investigation.
Sofia and Marcus each measured 10 cm³ of dilute hydrochloric acid into a test tube and measured the temperature. Then they each added an identical piece of magnesium ribbon to their test tube of acid. When the reaction stopped, they each measured the temperature again.
| Learner | Start temperature / °C | End temperature / °C |
|---|---:|---:|
| Sofia | 18 | 42 |
| Marcus | 21 | 45 |
Sofia and Marcus wondered how they could produce a higher temperature change. Their ideas included adding more magnesium, using a different metal and using a different acid.
Write each of these three ideas as a scientific question to be investigated.
Planning and carrying out an investigation into the reaction between acid and magnesium
Method
1. Choose one of the scientific questions to be investigated from question 8 (or write one of your own) and write a plan for your investigation.
- Before you write your plan, try out the reaction between magnesium and an acid. In this preliminary work you should practise measuring the temperature change.
- Decide what equipment you will need and make a list.
- You also need to find out how big a change in the variable (for example, the length of the magnesium ribbon) is needed to make a change in the temperature that you can measure.
- When the reaction takes place and chemical energy is changed to thermal energy, the thermal energy dissipates (spreads out) into the environment.
- Are you sure that you are measuring the temperature change accurately?
- What could you do to reduce this heat loss?
- Decide how you will record and present your results.
- Carry out a risk assessment.
2. Ask your teacher to check your plan.
3. Carry out your plan. You may find that you want to make changes to it once you begin doing the investigation. If so, write down the changes that you have made and explain why you made them.
