separating mixtures

Question	Answer
What is the difference between a compound and a mixture?	a compound is joined by a chemical bond whereas a mixture is purely physical
How can mixtures be separated?	• filtration • crystallisation • distillation • chromatography
filtration	• separating an insoluble solid from a liquid, ie. sand from water • the sand trapped is the residue and the water passing through is the filtrate
crystallisation	• separating a soluble solid from a liquid, ie. salt from water • a water bath can be used or the solution can be left to evaporate at room temperature
distillation	• separating two liquids with a significant difference in boiling points, ie. water from ethanol • the mixture is heated then the ethanol evaporates and cools in the condenser and is then collected as a pure liquid
Define miscible and immiscible liquids.	immiscible: liquids that do not dissolve into each other, ie. oil and water miscible: liquids that do dissolve into each other, often separated using fractional distillation
fractional distillation	• used if the boiling points of the two liquids are close, with a fractionating column
chromatography	• a separation technique used to separate and identify components of a coloured compound, ie. inks, dyes, colouring agents • as the solvent rises up the chromatogram, the dyes are separated, with different dyes travelling different distances up the paper

Resource summary

	Created by Farha Idrees over 6 years ago