last updated: Monday, February 02, 2015

1. Drying of apparatus:

The glass surface is polar (mainly silica based) and therefore absorbs water. This means that glassware that looks dry usually still contains a thin water layer on the surface which is invisible.

Since water poses a big problem in this reaction, the removal of water from the apparatus is very important. The student will use a heat gun. Generally, one starts from the bottom and works his way up to prevent the condensation of moisture on the cold glassware. The glassware should be hot to the touch!

After you are done heating, turn the switch on the heat gun to cold and allow the filament to cool down a little before you turn the heat gun off. Keep in mind that the noozle is still very hot (200-300 oC), so do not place it near flammable solvents or right on the white paper in the hood.

The heat gun should not be used at a later stage in the project to prevent fires.