Simple Distillation
EXPERIMENT 7 - Distillation – Separation of a Mixture
Purpose:
a) To purify a compound by separating it from a non-volatile or less-volatile material. b) To separate a mixture of two miscible liquids (liquids that mix in all proportions) with different boiling points. Equipment / Materials: large test tubes(3) clamp (1 or 2) ringstand boiling chips test tube rack (1) heating mantle glass adaptor thermometer adaptor 10-mL graduated cylinder condenser (1 or 2) grease 50- mL round bottom flask 50- mL round bottom flask thermometer rubber tubing (2) unknowns ( A and B)
Discussion:
Distillation is one of the oldest and still most common methods for both the purification and the identification of organic liquids. It is a physical process used to separate chemicals from a mixture by the difference in how easily they vaporize. As the mixture is heated, the temperature rises until it reaches the temperature of the lowest boiling substance in the mixture, while the other components of the mixture remain in their original phase in the mixture. The resultant hot vapor passes into a condenser and is converted to the liquid, which is then collected in a receiver flask. The other components of the mixture remain in their original phase until the most volatile substance has all boiled off. Only then does the temperature of the gas phase rises again until it reaches the boiling point of a second component in the mixture, and so on. The boiling point of a substance—determined by distillation—is a useful physical property for the characterization of pure compounds. At any given temperature a liquid is in equilibrium with its vapor. This equilibrium is described by the vapor pressure of the liquid. The vapor pressure is the pressure that the molecules at the surface of the liquid exert against the external pressure, which is usually the atmospheric pressure. The vapor pressure is a very sensitive function of temperature. It does not increase linearly but in fact increases
Purpose:
a) To purify a compound by separating it from a non-volatile or less-volatile material. b) To separate a mixture of two miscible liquids (liquids that mix in all proportions) with different boiling points. Equipment / Materials: large test tubes(3) clamp (1 or 2) ringstand boiling chips test tube rack (1) heating mantle glass adaptor thermometer adaptor 10-mL graduated cylinder condenser (1 or 2) grease 50- mL round bottom flask 50- mL round bottom flask thermometer rubber tubing (2) unknowns ( A and B)
Discussion:
Distillation is one of the oldest and still most common methods for both the purification and the identification of organic liquids. It is a physical process used to separate chemicals from a mixture by the difference in how easily they vaporize. As the mixture is heated, the temperature rises until it reaches the temperature of the lowest boiling substance in the mixture, while the other components of the mixture remain in their original phase in the mixture. The resultant hot vapor passes into a condenser and is converted to the liquid, which is then collected in a receiver flask. The other components of the mixture remain in their original phase until the most volatile substance has all boiled off. Only then does the temperature of the gas phase rises again until it reaches the boiling point of a second component in the mixture, and so on. The boiling point of a substance—determined by distillation—is a useful physical property for the characterization of pure compounds. At any given temperature a liquid is in equilibrium with its vapor. This equilibrium is described by the vapor pressure of the liquid. The vapor pressure is the pressure that the molecules at the surface of the liquid exert against the external pressure, which is usually the atmospheric pressure. The vapor pressure is a very sensitive function of temperature. It does not increase linearly but in fact increases