Distillation

1056 WordsFeb 28, 20135 Pages
Steam Distillation is the process of distilling a mixture wherein one of the immiscible phases is a steam. It is a mild method for separating and purifying volatile liquid or solid organic compounds that are immiscible or insoluble in water. This technique is not applicable to substances that react with water, decompose on prolonged contact with steam or hot water, or have a vapor pressure of less than about 5 torr at 100°C. One way to perform steam distillation is through the live steam method. It is the more widely used method. It is especially used with high molecular weight (low vapor pressure) substances. Although it requires more complex setup, this method reduces bumping. Principles Involved Live steam distillation is based…show more content…
6. Use an ice bath to increase the efficiency of condensation in the receiving flask. 7. Remove at least a tenth part of the distillate once it is already clear. 8. When distillation is to be stopped, the clamp in the water trap should be opened and the steam inlet tube must be removed from the three-necked flask (distilling flask). 9. Hot steam can produce severe burns so steam inlet tube must be cooled a little first before holding and attaching it to the distilling flask. 10. Cool the whole setup first before dismantling. 11. The thermometer bulb should be below the side-arm of the three-way adapter. 12. When droplets condensate at the thermometer bulb, the temperature reading is the boiling point. 13. When the first drop of liquid falls into the receiving flask, the temperature reading is the distillation temperature. 14. Cold water should constantly run through the lower half of the condenser and then water should go out of the top part of the condenser. 15. When a solid substance is placed in the distilling flask for the live steam method, water is not needed to be placed with it. 16. Cover joints or connections of two apparatuses with aluminum foil or Plaster of Paris to insulate it so steam vapors won’t condensate there. Reasons for Important Steps When the set-up is being assembled, make sure that the instruments are fastened securely to the ring stand. If the set-up calls for ground glass joints, lubrication is a need to assure that there would
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