separation techniques Flashcards
mobile phase
a gas or liquid where the molecules are able to move
stationary phase
a solid or thick liquid where the molecules are unable to move
solute
a substance dissolved in a solvent to make a solution
solvent
a liquid in which a solute can be dissolved
solution
a mixture mad up of one substance dissolved in another
why should you use pencil in chromatography?
it is insoluble and won’t dissolve in the solvent and affect the results
filtration
used to separate an insoluble solid from a liquid
chromatography
used to separate the substances in a mixture based on how the components interact with a mobile and stationary phase
crystallisation
the formation of solid crystals as water evaporates from a solution
insoluble
the solid can’t be dissolved in the liquid
crystallisation process
- pour solution into an evaporating dish and gently heat
- once some of the solvent has evaporated or you see crystals start to form, remove the dish from the heat and leave it solution to cool
- salt should start to form crystals as it becomes insoluble
- filter the crystals out of the solutions and leave them in a warm place to dry
evaporation process
- pour the solution into an evaporating dish
- slowly heat the solution
- keep heating until all you have left are dry crystals
when do you have to use crystallisation?
if the salt doesn’t decompose when its heated
simple distillation
used for separating a liquid from a solution
simple distillation process
- solution is heated, lowest boiling point evaporates first
- vapour is then cooled, condenses and is collected
- rest of the solution left behind in the flask