separation techniques

Question 1

what is the use of filtration

Answer 1

to separate an insoluble solid from a mixture

Question 2

what is residue and filtrate

Answer 2

the solid collected is residue
the liquid collected is called filtrate

Question 3

what is the set up of filtration

Answer 3

filter funnel, filter paper and beaker

Question 4

true/false

impurities lowers the melting points but raised the boiling points of substances

Answer 4

true

Question 5

what is the use of evaporation to dryness

Answer 5

to separate a soluble solid solute from a liquid solvent

Question 6

when the solution is heated, is the solvent or solute left behind

Answer 6

the solute is left behind (solute is the solid and solvent is the liquid)

Question 7

what is the use of crystallisation

Answer 7

to obtain a soluble solid(solute) from a solution. this technique can be used when the dissolved solid in solution is not heat stable

Question 8

state the process of crystallisation

Answer 8

1. evaporate the excess solvent in the solution to achieve a saturated solution
2. cool down the saturated solution to form crystals
3. filter the mixture to collect crystals as residue
4. wash the crystals with a small volume of cold distilled water
5. dry the crystals between two sheets of paper

Question 9

what is the use of simple distillation

Answer 9

to obtain a pure liquid from a solution

Question 10

how to evenly distribute the heat

Answer 10

use pieces of porcelain

Question 11

where must the bulb of the thermometer be placed and why

Answer 11

at the point where the vapour exits the distillation column and enters the condenser so that it would measure the boiling point of substance being distilled

Question 12

what is the use of sublimation

Answer 12

to separate two or more solids one of which can sublime