Which method is effective for purifying a liquid through heating and cooling?

The effective method for purifying a liquid through heating and cooling is distillation. This process takes advantage of the differences in boiling points among the components of a mixture. During distillation, the liquid mixture is heated until one or more of its components reach their boiling point and vaporize. The vapor then travels through a cooling system, where it condenses back into a liquid form. This condensed liquid, known as the distillate, is collected separately from the remaining components that have higher boiling points and remain in the original container.

By controlling the temperature during this process, distillation can separate and purify substances based on their volatility, making it a highly effective method for isolating specific liquids from mixtures. This technique is commonly used in laboratories and industries for various applications, including the production of distilled spirits, the purification of water, and the refinement of petrochemicals.