Heidolph LABOROTA 20 compact and safety - Manual (Page 67)

67
E

The line gradient is a function of enthalpy of evaporation. It is similar for chemically related
substances with boiling points close to each other. Hence, the plotted lines may be used as a
guide for substances with slightly different boiling points.

Using a water-jet or diaphragm-type pump, you may lower boiling point by approx. 100°C.

Rule of thumb: decrease pressure to a half will lower boiling point by approx. 15°C.
Avoid overpressure in the glassware kit while distilling low-boiling solvents. Aerate
glassware kit as required. Overpressure in the glassware kit may damage the evaporator
or even blow-up parts of the glassware kit.