Insulation and antifreeze

Tender and supervisor checking diver's equipment prior to dive
Divers use dry suits and layers of thermal clothing to keep warm underwater (Photo: Glenn Johnstone)

Investigate antifreeze formulas and the thermal properties of materials. Record your predictions, discuss your final results and the implications for clothing and building insulation.

  • Students can discover their own antifreeze formula by adding a variety of substances to water and placing them in a freezer. Half-fill each of several plastic containers (all the same size) with water. Add a different substance (e.g. rock salt, sugar, vinegar, lemon juice etc) to each and label. Freeze overnight, remove and observe the results.
    • Did all the containers' water freeze?
    • Was ice more prevalent in one container than another?
  • As a follow-up activity, try adding substances to make the water freeze more quickly.
  • Students can investigate the thermal properties of materials, and discover which materials make the best insulators. Groups can be set up to run parallel experiments, each group with a different material (such as newspaper, plastic sheet, cotton wool, metal foil, wool, fur, polar fleece, cotton, nylon) but experimenting with, for example, different thicknesses. Students should record their predictions about which material will be the best insulator and the effect of thickness, and then discuss their final results (twice the thickness gives better insulation, but is less than twice as good).
  • Students can then discuss the implications for clothing, and for insulation in buildings.
  • Put the same amount of hot water into several identical jars.
    • Label the jars and record the temperature of each.
    • Wrap each jar in a different material.
    • Either place jars in freezer for 30 minutes, then remove jars and record the temperatures again. Or leave jars and measure the temperature of water in each jar every 15 minutes.
    • Graph the results.
This page was last modified on July 3, 2014.