Methods of Purification

Question 1

evaporation: method

Answer 1

the solution can be heated so that the liquid evaporates completely and leaves the solid behind.

Question 2

crystallisation: method

Answer 2

heating a solution to leave make it saturated, and then leaving it to crystallise.

Question 3

simple distillation method

Answer 3

used to obtain the solvent from a solution. the solution is heated in the flask until it boils. the steam rises into the liebig condenser, where it condenses back into water. the salt is left behind in the flask.

Question 4

fractional distillation

Answer 4

usdd to seperate liquids that are miscible. (eg water and ethanol)

when the mixture is hated the vapour produced is mainly ethanol with some steam. because water has a higher boiling point, it condenses out from the mixture with ethanol. the water condenses and drips back into the flask. the ethanol vapour moves up the fractionating column and into the condenser, where it condenses into liquid ethanol and is collected in the receiving flask