States of matter > change of state

In this demonstration the gaseous halogen, chlorine, is 

In this class practical students take the temperature of stearic acid at regular intervals as they heat and cool it. They can observe the

Evaporation is the conversion of liquid to vapour without the boiling point necessarily being reached. In this experiment, the time taken for a drop of propanone to evaporate is measured under a number of different 

Students melt sodium thiosulfate crystals, and these are then cooled to a state well below the melting point. The melt now exists in a metastable supercooled state. The supercooled liquid will freeze rapidly on the addition of a crystal of sodium thiosulfate or dust particles, or on stirring. Students

Pieces of solid air freshener are heated in a hot waterbath and the vapour caught by cooling with ice. No liquid will be observed so students will be able to appreciate that a solid has turned directly to a gas without passing