Sublimation

Sublimation is the change of state from solid to gas without passing through the liquid state. This experiment examines how iodine behaves on heating.

Sublimation is a change of state in which matter passes from the solid state directly to vapour.

In the case of some substances such as iodine, naphthalene etc, sublimation occurs quite easily because the solids have quite a high vapour pressure. Their vapour pressure becomes equal to atmospheric pressure before the melting point is reached and so the solid passes straight from solid to vapour without melting.

• Test tubes — 1473.60
• Test tube rack — 1680.06
• Test tube holder — 5423.30
• Spatula — 5460.34
• Spirit burner — 5514.10

• Iodine — R:20/21-50 S:23-25-61
• Acetone — R:11-36-66-67 S:9-16-26

• This experiment must be performed in a fume cupboard or outdoors.
• Take care when using the burner and hot glassware.

• Record your observations of what happens.