Identify the substance that has the greatest amount of energy explain your choice. 1. An ice cube at 0°C or a recently melted ice cube at 0°C. 2. A puddle of isopropyl alcohol or evaporated isopropyl alcohol (both are at the same temperature).
Answers
Answer:
The Energy of Evaporation | A Lab Investigation
Summary
In this investigation, students test evaporation rates for different liquids. Next, students use a
thermometer to measure the temperature change during evaporation.
Objective
Students will explore the energy change associated with evaporation and the differences in
evaporation rates of different liquids.
Safety
• Be sure you and the students wear properly fitting goggles.
• Isopropyl alcohol and acetone are flammable and should be handled with care. Avoid
flames or sparks, and work in a well-ventilated area. Avoid body tissue contact.
• Do not substitute plastic cups for glass beakers in this experiment, as acetone will dissolve
some plastic cups.
Materials for Each Group
• 4 student thermometers
• 5 paper towels
• 4 small rubber bands
• Tape or sticky labels
• 3 droppers
• Water
• 99% isopropyl alcohol
• Acetone
• 3 small glass beakers (50–150 mL)
• 3 graduated cylinders (10–100 mL)
Time Required
One class period, approximately 45–50 minutes.
Lab Tips
Because water can take a long time to evaporate, you may wish to have students move on to the
second part of the investigation after recording evaporation times for acetone and isopropyl
alcohol. Note that evaporation times may vary according to humidity and air currents.
Integrating into the Curriculum
This investigation could be incorporated into a unit on phase changes, chemical and physical
changes, and energy.