Question 75
Mia investigated what happened when each of four white solids, A to D, was mixed with water.
- She put 20 cm³ of water into each of four test tubes labelled A to D.
- She measured and recorded the temperature of the water in each test tube.
- For each test, she put 5.0 g of a solid (A, B, C or D) into the corresponding test tube.
- She stirred the solid and water in the test tube for one minute.
- She then measured and recorded the temperature of the mixture.
These are Mia’s results.
| Solid | Temperature of water at the start (°C) | Temperature of mixture at the end (°C) |
|---|---|---|
| A | 20 | 30 |
| B | 20 | 22 |
| C | 20 | 20 |
| D | 20 | 16 |
Did Mia’s investigation involve a physical or chemical change? Say why.
- She put 20 cm³ of water into each of four test tubes labelled A to D.
- She measured and recorded the temperature of the water in each test tube.
- For each test, she put 5.0 g of a solid (A, B, C or D) into the corresponding test tube.
- She stirred the solid and water in the test tube for one minute.
- She then measured and recorded the temperature of the mixture.
These are Mia’s results.
| Solid | Temperature of water at the start (°C) | Temperature of mixture at the end (°C) |
|---|---|---|
| A | 20 | 30 |
| B | 20 | 22 |
| C | 20 | 20 |
| D | 20 | 16 |
Did Mia’s investigation involve a physical or chemical change? Say why.
