Simple and Steam Distillation
Distillation is a physical method of separating a highly volatile compound from a less-volatile or non-volatile compound depending upon the difference in the boiling point of the component substances. This experiment focuses two distillation types, which are the simple and steam distillation, for the purification of compounds having different properties. The main objectives are to be able to assemble a simple and steam distillation set-up, to be able to identify and recognize the significant of all its parts and to be able to purify the sample. In Simple Distillation, we used 15 mL of impure carbon tetrachloride and boiled it in a continuous high temperature to produce an impure distillate too. The sample was orange coloured first but afterwards, it became colourless. Percent Recovery was also determined by dividing the volume of the distillate over the volume of the impure carbon tetrachloride and multiplied it to 100%. On the other hand, in Steam Distillation, we used impure p-dichlorobenzene and boiled it at a lower temperature that consumed more time. This resulted to crystal formation clogging the condenser and was slowly heated using Bunsen burner. The recovered substance is in the form of white crystals after directly subjected to cold water bath. This gave purer distillate, but is only applicable to be used in aromatic compounds. We used glass beads to prevent bumping and to avoid the solvent to be superheated. These are made of a porous material and have a nonreactive. On both type of distillation, running water was used to force the vapor to go back to being a liquid thus producing the distillate.
Keywords: distillation, Simple distillation, Steam distillation, volatile, non-volatile, distillate, glass beads[pic] INTRODUCTION
A unit operation used in separating mixtures based on differences of boiling points is called distillation. Its main goal is to purify the organic compounds through heating a mixture at a specific temperature and collecting the hot vapours. Then, condense to separate the component substance. Among its common types, this experiment only focuses on the steam and simple distillation. Simple distillation is used to separate a single volatile component from the rest of a mixture. A very simple example would be to obtain pure water from sea water. It is designed to evaporate a volatile liquid from a solution of non-volatile substances; the vapor is then condensed in the water condenser and collected in the receiver. In simple distillation, all the hot vapors produced are immediately channeled into a condenser that cools and condenses the vapors. Therefore, the distillate will not be pure - its composition will be identical to the composition of the vapors at the given temperature and pressure. As a result, simple distillation is usually used only to separate liquids whose boiling points differ greatly or to separate liquids from in volatile solids or oils. The principle of the steam distillation is when a mixture of two practically immiscible liquids is heated while being agitated to expose the surfaces of both the liquids to the vapor phase, each constituent independently exerts its own vapor pressure as a function of temperature as if the other constituent were not present. Consequently, the vapor pressure of the whole system increases. Boiling begins when the sum of the partial pressures of the two immiscible liquids just exceeds the atmospheric pressure (approximately 101 kPa at sea level). In this way, many organic compounds insoluble in water can be purified at a temperature well below the point at which decomposition occurs. Steam distillation is sometimes used to separate intermediate or final products during the synthesis of complex organic compounds. The purposes of this investigation were to assemble a simple and steam distillation set-up, to identify and recognize the...