Which term best describes a method to increase the purity of a liquid by boiling it?

The term that best describes a method to increase the purity of a liquid by boiling it is distillation. This process involves heating a liquid until it vaporizes, then cooling the vapor to collect the condensed liquid. The benefit of distillation is that it separates components of a mixture based on their different boiling points, thereby allowing for the purification of the liquid.

During distillation, impurities that have higher boiling points remain in the original container, while the more volatile (lower boiling point) component is collected as it vaporizes. This makes distillation particularly effective for separating solvents from solutes or for purifying liquids that need to be free of contaminants.

Other methods listed, such as decantation, absorption, and filtration, serve different purposes in the separation and purification of mixtures but do not specifically involve the process of boiling a liquid to achieve higher purity, which is the key function of distillation.