Seperations Flashcards
Explain how paper chromatography works
It separates a mixture of soluble substances like inc and food colouring
In paper chromatography the stationary phase is the paper and the mobile is the solvent
In thin layer the stationary is the alumina or silica and mobile is the solvent
STEP 1 draw a line in pencil on a piece of chromatography paper
STEP 2 put a spot of the substance your testing
STEP 3 put a small abit of solvent in beaker
STEP 4 put the chromatography paper in the beaker so it just touches the solvent
STEP 5 cover the beaker so the solvent doesn’t cause any evaporation
You then can see what’s happened to the substance your testing
What is the solute
The solute dissolves in the solvent
Eg salt or sugar
What is a solvent
The liquid the solute dissolves in
Eg water or ethanol
Explain how distillation works for salty water
Put the salty water in a flask then heat this flask to 100 degrees the water will then evaporate up a tube which will cool down to fall into a new flask that will then contain only water as the salt will be left behind as it doesn’t boil at 100 degrees
Explain how filtration work
Filtration separates an insoluble solid from a liquid
You will pour the liquid into the funnel which contains filtration paper the liquid will get through the paper leaving the insoluble solid behind
Explain how crystallisation works
This will separate a solvent from a solute
First heat the solution this will cause the solvent to evaporate and the solute to stay behind
The solute is then left behind when the solvent is gone and starts to form crystals
Leave the crystals to dry and form
Explain how to use fractional distillation to separate ethanol and water
Fractional distillation separates 2 liquids with different boiling points
First heat the flask they are in at 78 degrees ethanol will evaporate
Second the water will evaporate when at 100 and condense back from water vapour giving you pure water in a new flask with no ethanol
