Passage
Students studied how long it takes water to freeze solid. In each trial they poured a measured amount of water into an identical cup, placed it in a freezer, and recorded the time in minutes until the water had frozen completely.
Study 1: Using the same 100 mL sample of water, the students placed it in freezers set to different temperatures and recorded the freezing time (Table 1).
| Freezer temperature (°C) | Freezing time (min) |
|---|
| -5 | 95 |
| -10 | 58 |
| -15 | 41 |
| -20 | 32 |
| -25 | 27 |
Study 2: Holding the freezer temperature at -15°C, the students froze different starting volumes of water and recorded the freezing time (Table 2).
| Water volume (mL) | Freezing time (min) |
|---|
| 50 | 22 |
| 100 | 41 |
| 150 | 62 |
| 200 | 84 |
The same kind of cup and the same freezer were used in every trial.
