In fractional distillation, at what point do vapors condense?

The correct answer highlights that vapors condense when they are cool enough. In the process of fractional distillation, different components of a mixture are separated based on their boiling points. As the mixture is heated, various components vaporize at different temperatures.

Once these vapors rise through the column, they encounter cooler surfaces. When the temperature of the vapor decreases and reaches its condensation point, the vapor turns back into liquid. This is because the energy of the vapor molecules decreases as they cool, allowing intermolecular forces to pull them together into a liquid phase. The efficient separation in fractional distillation relies on this cooling and condensation process, allowing for the collection of purified liquids at different heights in the column, based on the specific temperature at which each component condenses.

This understanding is critical to appreciate how fractional distillation effectively separates mixtures, such as in the petroleum industry for refining crude oil, where various hydrocarbon fractions are obtained at specific temperatures.