Freezing and Melting of Water

Hypothesis: If the water is normal, then the freezing and melting points will be 0° C (32°F).

In the graph below the red line shows the freezing of the water (ironic huh). The blue line shows the water melting

Results: I found that the freezing temperature was correct at 0° C (32°F). Although, the melting temperature was a little higher than expected at 0.9°C (34°F). I accepted my hypothesis of the freezing and melting points of water. Some possible errors could be the temperature probe malfunctioned. Maybe, the temperature changed from an accidental touch.

1. What happened to the water temperature during freezing? During melting? The water temperature dropped sharply during freezing. When melting occurred the temperature rose much slower.

2. According to your data and graph, what is the freezing temperature of water? The melting temperature? Express your answers to the nearest 0.1°C. The freezing temperature of water was about

0° C. The melting point was a little higher at 0.9° C.

3. How does the freezing temperature of water compare to its melting temperature? The freezing temperature of water was just under a degree lower than the melting temperature. Room temperature is about 30° C.

4. Tell if the kinetic energy of the water in the test tube increases, decreases, or remains the same in each of these time segments during the experiment.

a. when the temperature is changing at the beginning and end of Part I

The kinetic energy drops. This is because as molecules cool down, they loose energy.

b. when the temperature remains constant in Part I

The kinetic energy remains the same due to a lack of temperature change.

c. when the temperature is changing at the beginning and end of Part I

The kinetic energy increases as the temperature does.

d. when the temperature remains constant in Part II

The kinetic energy would stay the same due to a lack of change in temperature.

5. In those parts of Question 4 in which there was no kinetic energy change, tell if potential energy increased or decreased. The potential energy increased. The lower the kinetic energy the higher the potential energy.