To purify an unknown liquid by simple distillation 2. To determine the boiling point of an unknown liquid 3. To determine the identity of the unknown liquid by comparison of the boiling point determined with known values for known compounds.
Distillation is a process by which a liquid can be purified.
A liquid at any temperature exerts a pressure on its environment. This pressure, known as the vapor pressure, results from molecules leaving the surface of the liquid to become vapor and occurs due to random molecular motion. During distillation, a liquid is placed in a round bottom flask and heated. This results in an increase in the kinetic energy of the molecules causing the equilibrium to shift in the favor of the vapor phase, thus increasing the vapor pressure. When the vapor pressure of the liquid equals the total pressure exerted on its surface, the liquid begins to boil.