Distilled water is produced by boiling normal tap water or pre-purified water, whereby the condensed steam is immediately collected. It is largely free of salts, organic substances and microorganisms; however, it may still contain small amounts of volatile compounds.

Distillation is a process that can be used to separate liquids, solvents and solutions. It is a very useful method for separating the different components of a mixture, even if they are difficult to separate using other methods.

The first thing you need to do is heat your mixture until it boils. The steam that is produced when water boils is called vapor and contains all the different molecules (or "volatiles") from your solution. You then need to cool the steam so that it becomes liquid again - this process is called condensation. To do this, you use what is known as a condenser - on a small scale you can use a Liebig condenser. The liquid that drips out of the condenser contains all the molecules of the original mixture!

There are two main types of distillation: wet distillation and dry distillation. In wet distillation, the liquid does not decompose during the distillation process, although it can vaporize at a temperature lower than the boiling point of the liquid. In dry distillation, on the other hand, the non-vaporizable solids are broken down into smaller molecules. Dry distillation of wood, for example, produces "wood alcohol" (methanol). Although a vaporizable liquid is obtained here by condensation, according to current theory no distillative separation takes place. This process is therefore better known as thermolysis or pyrolysis.

Distillation is a process in which liquids are heated and cooled in order to separate them into their components. To do this, a mixture of two or more liquids is heated until they evaporate and the resulting vapor is then cooled so that it condenses back into liquid form. The different components of the mixture have different boiling points, so that each condenses at a different temperature.

The simplest distillation is "simple distillation", in which a mixture of two or more liquids is heated until all the substances it contains evaporate. This is done at different temperatures for each substance, so that the substance with the lowest boiling point vaporizes first, followed by the substances with higher boiling points. When all the substances have evaporated, what remains is mainly vapor and very little liquid - or none at all!

When a liquid is brought to boiling point in a pot on the stove, the water turns into steam. The composition of the gas phase above the boiling liquid is that indicated by the dew point curve at the same temperature (horizontal line). Condensation produces a liquid whose composition corresponds to that of the gas phase, i.e. it contains an increased proportion of the lower boiling component 2 (vertical line). So if you observe what happens in your pot as it boils, you will notice that initially there is more vapor than liquid, but as it continues to boil and condenses again, this ratio shifts in favor of the vapor.

In addition, some of the remaining liquid in the low-boiling component is consumed over time, causing the horizontal line to shift upwards.