Separation Techniques Flashcards
what are the separation techniques?
filtration, evaporation, crystallization, distillation, extraction
what materials does the filtration separation technique use?
filter paper and funnel
what is filtration and what is it used for?
it is used to separate insoluble solids within liquids.
what is evaporation and what is it used for?
it is used for separating dissolved solids in liquids . it features the extreme heating of a solution until the solvent vaporizes and leaves the solute dry
what materials are used in evaporation and how does the technique work?
a bunsen burner is used to heat an evaporating dish, which heats the solution and allows the solvent to completely disappear/evaporate. this process leaves behind dry crystals
what is the benefits of evaporation?
its fast and easy, and does not always require heating instruments (for example, we can use the sun in order to dry clothes, etc…)
what is the downside of evaporation?
the intense heat may break down/decompose certain solutes or form impurities
what is crystallization and what is it used for?
its also used for dissolved solids in liquids, but this technique is more gentle than evaporation. it involves controlled heating and cooling time
what is the process of crystallization?
heating the solution (until crystals start forming), cooling it down, then filtering out the crystals
what is distillation and what is it used for?
it is used to separate dissolved liquids in a solution
what is the process of distillation?
heating up of a solution in a distilling flask, which evaporates one of the liquids in the mixture while leaving the other one in liquid form. as the gas evaporates and rises, it enters the condenser and, due to the water jacket, becomes cooler and returns to a liquid state that gets put into a receiving flask.
what is extraction?
it is the technique that relies on solubility and density. it often uses a solvent to selectively dissolve one substance while leaving the others behind.
what is the effect of cooling time in crystallization?
longer cooling time would mean purer and larger crystals, while shorter cooling time would mean the opposite
what is fractional distillation and what is it used for?
fractional distillation is used for separating liquids with close boiling points. this differs from normal distillation as it includes a fractionating column. this column includes glass rods or beads that increase the surface area for condensation, allowing for the vapor of one component to pass through, while the other is condensed and returned to the distilling flask.
what are the types of extraction?
liquid liquid, solid liquid
what is liquid liquid extraction?
this is used for two immiscible (doesnt mix) liquids, which are usually aqueous liquids and organic liquids. it essentially pulls out a compound/substance from solvent A and moves it to solvent B as a result of the difference of solubility. the substance may “prefer” another solvent and redistribute itself. ex. decaf coffee. initially, caffeine is within water, but it is more soluble in an organic liquid. if you mix coffee with an organic liquid and shake it, the caffeine will move itself to the organic liquid. due to a difference in density and due to the fact that they are immiscible, there will be two distinct layers of the mixture, which makes it possible to separate the two liquids with a separatory funnel and a stopcock.
what is solid liquid extraction?
it is a technique that is also known as leeching. it involves extract a solute from a solid mixture by using a liquid solvent. it works by placing the solid mixture into the liquid solvent. the liquid solvent is then only able to dissolve the soluble parts of the solid mixture, thus extracting the solute. the remaining insoluble parts is then separated. ex. tea leaves. we can add tea leaves (solid mixture) to water. the water is only able to extract/dissolve the soluble parts of the tea leaves (caffeine, flavor, color,…), but it leaves the actual leaves (insoluble part) behind
