Question 11
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?
| 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?
