1.4: Fractional Distillation And Paper Chromatography Flashcards
What is fractional distillation used for?
Fractional distillation is used to separate miscible liquids, such as ethanol and water.
What does the term ‘miscible’ mean?
Miscible describes liquids that dissolve in each other, mixing completely.
How does fractional distillation work?
Fractional distillation works by using a fractionating column to separate liquids based on their different boiling points.
What is the role of the fractionating column in fractional distillation?
The fractionating column allows vapours to pass over glass beads, condensing higher boiling point substances back into the flask.
At what temperature should ethanol be collected during fractional distillation?
Ethanol should be collected at around 80°C, as its boiling point is 78°C.
How can you test for the presence of ethanol in a distillate?
You can test for ethanol by applying a lighted splint to a small volume; it will ignite if ethanol is present.
What is paper chromatography used for?
Paper chromatography is used to separate and identify substances from mixtures in solution.
How does paper chromatography separate substances?
It separates substances based on their different solubilities in the chosen solvent.
What is the setup for a paper chromatography experiment?
A spot of the solution is placed on chromatography paper, which is then placed in a solvent in a beaker.
What can be deduced if substance B travels further than substance A in chromatography?
Substance B is more soluble in the solvent than substance A.
What are some other methods of chromatography mentioned?
Thin-layer chromatography (TLC) and gas chromatography (GC) are other methods of chromatography.
What is a key point about fractional distillation?
Fractional distillation is effective for separating miscible liquids due to their different boiling points.
What is a key point about paper chromatography?
Paper chromatography separates mixtures based on the different solubilities of substances in the solvent.
