When making distilled water in the laboratory, cooling water should be introduced first. First, enough water should be injected into the pot to prevent the heating wire inside from burning out. Second, the stainless steel pipeline inside should be cooled to cool the steam.

If the alcohol lamp is turned on first, and then distilled water is introduced, the glass tube of the condenser is heated by turning on the alcohol lamp first, and then cooling water is introduced, the glass tube will suddenly cool down, which may lead to the glass tube breaking.

Extended data:

After distillation, stop heating first, then stop water supply, and dismantle the instrument. Disassembly of the instrument is in the reverse order of assembly. First remove the receiver, then remove the tail pipe, condenser pipe, distillation head and distillation bottle.

Attention during operation:

(1) Put a small amount of broken porcelain pieces in the distillation bottle to prevent the liquid from boiling.

(2) The mercury ball position of the thermometer should be on the same horizontal plane as the lower end of the branch nozzle.

(3) The liquid contained in the distillation bottle should not exceed 2/3 of its volume and should not be less than 1/3.

(4) The cooling water in the condenser tube enters from the lower mouth and is discharged from the upper mouth.

(5) The heating temperature should not exceed the boiling point of the substance with the highest boiling point in the mixture.