Phase Change Lab

Question:

How will the temperature of a substance (water) change as heat energy is added?

Background:

The atoms of matter are in motion. This motion corresponds to the material's internal energy.

Hypothesis:

Equipment:

  1. hot plate
  2. 400 ml beaker
  3. thermometer
  4. stirring rod
  5. ice water

Safety:

Be very careful with the hot plates, glassware and water.
If you want to check if it is warm, put the top of your hand ABOVE it.
Hot glass does not look any different from cool glass.
Safety goggles must be worn at all times throughout the lab.

Procedure:

  1. Add 200 ml of ice water (with ice cubes) to the empty beaker.
  2. Verify your hot plate is off and cool. Make sure the bottom of your beaker is DRY.
  3. Place the beaker on the hot plate.
  4. Adjust the ring stand clamp so just the bulb of the thermometer is below the water surface.
  5. After the readings have stabilized, record the temperature of the ice water.
  6. You may wish to stir the water, but be very careful not to touch the thermometer.
  7. After one minute, measure and record the temperature again.
  8. Turn on the hot plate and set it to 80% of maximum.
  9. Measure the temperature every minute until the water starts to boil.
  10. Take three more temperature readings (3 more minutes) after the water is boiling.
  11. Turn off the hot plate and unplug it. Do NOT touch the beaker.

Data Table:

Make a table showing the time in minutes and temperature reading.

Graph:

Graph the data you have gathered with the IV on the x-axis and the DV on the y-axis.
Refer also to the lab report format section on graphing.
  1. Label the point on your graph when the all the ice was melted .
  2. Label the point on your graph when the water started to boil.

Conclusion:

Refer to the lab report format and write a conclusion for this lab.
Be sure to discuss:
  1. the water temperature while the ice was melting.
  2. the water temperature after the ice melted, but before it started boiling.
  3. the water temperature as the water was boiling.
  4. how could the temperatures plateaud while still adding energy?

Get a copy of the instructor's typical data set graph (time vs. temperature readings).
If your graph doesn't resemble the this graph,
to address this in your error discussion.