1. Analyzing Data Practice
Phase Changes

2. If a beaker of rubbing alcohol and a beaker of water were both placed into a freezer with a temperature of -2 °C, what would be the result? Explain.
If rubbing alcohol and water were both put in a freezer at a temperature of -2 ⁰C, the water would freeze and the rubbing alcohol would stay liquid. This happens because of the freezing points of both liquids. When a temperature is below the freezing point of a substance, that substance will become a solid. Water freezes at 0 ⁰C. Because -2 ⁰C is below 0 ⁰C, the water would freeze. However, rubbing alcohol freezes at ⁰C. Since -2 ⁰C is above ⁰C, the rubbing alcohol will stay liquid.

3. Which substances in the chart would be solid at room temperature (25 °C)? Explain.
The substances that would be solid at room temperature are zinc chloride, magnesium chloride and sodium chloride. Each of these substances has a melting point above 25 ⁰C. The melting point of zinc chloride is 290 ⁰C, the melting point of magnesium chloride is 714 ⁰C and the melting point of sodium chloride is ⁰C. Because these temperatures are above 25 ⁰C, all three of the substances will be solids at room temperature.

4. Rubbing alcohol and water are both clear liquids
Rubbing alcohol and water are both clear liquids. How could you determine if a clear liquid was rubbing alcohol or water using the information from the chart? Explain.
You could determine the difference between the two substances by placing them in a freezer. A normal kitchen freezer has a temperature of -2 ⁰C. When placed in a freezer, the water will freeze because its freezing point is 0 ⁰C, which is the temperature liquid water will turn into a solid. This is above the freezer’s temperature. However, the freezing point of rubbing alcohol is ⁰C. Because this temperature is below the temperature of the freezer, the rubbing alcohol will stay liquid.