Distillate
Definition and meaning of Distillate in chemistry.
Distillate is the liquid product obtained by cooling and condensing the vapor produced during distillation, a separation technique based on differences in volatility.
In more detail
When a liquid mixture is heated, the vapor rising from it is enriched in the more volatile (lower-boiling) component relative to the liquid below. Passing this vapor through a condenser cools it back into a liquid, the distillate, which is collected separately from the less volatile material left behind in the boiling flask (the residue or "bottoms"). Because vapor-liquid equilibrium rarely gives complete separation in a single step, achieving high purity often requires fractional distillation, in which repeated vaporization-condensation cycles occur along a fractionating column.
Key facts
| Field | General Chemistry |
|---|---|
| Formed by | Condensation of vapor produced during distillation |
| Common uses | Purifying liquids, separating mixtures, desalination, alcohol production |
| Related process | Fractional distillation improves separation via repeated vaporization-condensation cycles |
Distilling a saltwater solution produces a distillate of pure water vapor that condenses in the receiving flask, while the nonvolatile dissolved sodium chloride remains behind in the original vessel.
Frequently asked questions
What is the difference between a distillate and the residue?
The distillate is the condensed liquid enriched in the more volatile component of the original mixture, while the residue (or bottoms) is the less volatile material that stays behind in the distillation flask.
Is a distillate always completely pure?
Not necessarily. A single simple distillation often only partially separates components, especially if their boiling points are close or they form an azeotrope; fractional or repeated distillation is usually needed for high purity.