Required practical - investigating methods of insulation part 1

There are different ways to investigate methods of insulation. In this practical activity, it is important to:

  • make and record measurements of temperature and time accurately
  • measure and observe the effect of different materials as thermal insulators
  • use appropriate apparatus and methods to measure the effectiveness of different materials as thermal insulators

Aim of the experiment

To compare the effectiveness of different materials as thermal insulators.

Beaker with water in another empty beaker, covered with card on top. Thermometer put through card into small beaker, and a stopwatch on the side reading 00:00.

Method

  1. Place a small beaker into a larger beaker.
  2. Fill the small beaker with hot water from a kettle.
  3. Put a piece of cardboard over the beakers as a lid. The lid should have a hole suitable for a thermometer.
  4. Place a thermometer into the smaller beaker through the hole.
  5. Record the temperature of the water in the small beaker and start the stopwatch.
  6. Record the temperature of the water every 2 minutes for 20 minutes.
  7. Repeat steps 1-6, each time packing the space between the large beaker and small beaker with the chosen insulating material.
  8. Plot a graph of temperature (y-axis) against time (x-axis).

Results

Time (mins)No insulation (°C)Material 1 (°C)Material 2 (°C)
0.........
2.........
............

Analysis

Plot all of the curves on the same axes. This will make the materials easier to compare.

Graph plotting time against temperature. 5 downward curves, each representating a different material. All curves start at 100 degrees and are measured for 20 minutes.

This graph shows:

  • The curve which takes the longest time for the water temperature to drop (the shallowest) should be the material which is the best insulator.
  • The temperature falls quickly at high temperatures and slowly at low temperatures.
  • When the beaker is at a high temperature, there is a big difference between the temperature of the beaker and the temperature of the surrounding air. This means there is a high rate of transfer.
  • When the beaker is at a lower temperature, there is less difference between the temperature of the beaker and the temperature of the surrounding air. This means there is a lower rate of transfer.

Hazards and control measures

HazardConsequenceControl measures
Boiling waterScald skinDo not overfill the kettle. Place the small beaker inside the large beaker before gently pouring the water. Remember to place any scald under cold running water for at least 10 minutes.
Knocking beaker off the deskScald skinPlace the beaker away from the edge of desk. Carry out the experiment whilst standing.