Separation Techniques Flashcards
What is filtration used for?
To obtain an insoluble solid from a solid-liquid suspension.
What is “Evaporation To Dryness” used for?
To obtain a soluble solid that is stable to be heated from a solid-liquid solution.
What is “Crystallization” used for?
To obtain a soluble solid that is unstable to be heated from a solid-liquid solution.
Explain what happens when the unstable soluble solid gets overheated during crystallization?
It will decompose when all the water is removed from it. Liquid is evaporated (about 1⁄3 its volume left) until a saturated solution is
obtained.
What is simple distillation used for?
To obtain a liquid from a solid-liquid solution.
What is fractional distillation used for?
To obtain a liquid from a liquid-liquid solution (Miscible Liquids).
How does one separate liquids of different densities?
Place both liquids (E.g. Oil & Water) into a separating funnel. The mixture will separate into two distinct and separate layers. The tap of the separating funnel will allow the bottom layer to flow out.
How does one test a purity of a liquid?
Heat the liquid and observe if it boils at a fixed temperature.
What is the purpose of boiling chips?
To smoothen the boiling process and prevent superheating of the liquid being distilled and they will cause a more controlled boil.
What must be achieved for crystallization?
1/3 of the liquid must be left such that the liquid is saturated. This will cause the solvent to push the solid out.
Why must be there be glass beads in the set-up of fractional distillation?
It is to provide large surface area for repeated evaporations and condensations of the liquids to take place and the liquid to be separated.
