I4-11. Boiling At Reduced Pressure

Purpose

To demonstrate that water boils at a lower temperature under reduced pressure.

Equipment

Flask with water inside plastic liner, hot plate, dry ice and gloves.

Suggestions

Handle with care. Be sure stopper is loose when heating the water.

Setup Time

15 min. (Dry ice must be obtained from Chemistry.)

Images

Descrption

Water is boiled in the flask, then heat is removed and the flask is sealed after boiling ceases. Dry ice is packed around the flask, reducing the pressure inside the flask. The boiling immediately resumes.