Mass and Heat of Phase Change over Time (Kari Kelly)

Title

Temperature and Phase Changes over Time

Author(s)

Kari Kelly

Question

How will the temperature change over time?

How long will the water stay in each phase?

What are the ranges of temperatures for each phase?

Using the heat capacity of water, calculate the specific heat capacity of water (Joules)?

Old Standards

High School Chemistry:

2d. Students know the atoms and molecules in liquids move in a random pattern relative to one another because the intermolecular forces are too weak to hold the atoms or molecules in a solid form.

4d. Students know the values and meanings of standard temperature and pressure (STP).

7a. Students know how to describe temperature and heat flow in terms of the motion of molecules (or atoms).

7c. Students know energy is released when a material condenses or freezes and is absorbed when a material evaporates or melts.

Experimental Design

Students will be measuring the temperature and phase changes over time of 100 mL and 200 mL, of distilled water. Students will be filling beakers with ice of the different volumes, recording the temperature every minute, graphing the results and comparing their graphs of each volume of water.

Independent variable

Time (minutes)

Dependent variables

Temperature (degrees Celsius)

Series

Compare the graphs of two different volumes of water.

Controls and Constants

The control would be distilled water and using the same size and brand of beaker. The constant would be pressure - and the same heat setting on the hot plate.

Materials

crushed ice, beakers (two 250mL), thermometer, hot plate, timer, ring stand, test tube clamp

Procedures

1. Students will weigh a beaker, fill it with 100mL of crushed ice and place a thermometer into a test tube clamp on the ring stand submerging it into the ice and beaker, being careful that the bulb of the thermometer doesn't touch the bottom of the beaker. Take initial temperature.

2. Place the beaker onto a pre-heated hot plate (set to 400 C) and start timer.

3. Record the temperature every minute (60 seconds) until the water boils

4. Graph your data

repeat steps 1-4 for 200mL of crushed ice.

Sample data and graphs

Photographs and Movies

Bill Nye Heat Clip

Changes in states of matter

References

Heat Capacity of Water and Temperature.

USGS and Water

Practice Worksheet