topic 2

Question 1

simple distillation method

Answer 1

heat solution
solvent evaporates
solute has a higher boiling point so
solute remains

Question 2

fractional distillation method

Answer 2

heating -> evaporating -> cooling -> condensing

works when liquids have different boiling points

Question 3

fractional distillation and oil

Answer 3

oil heated in fractionating column
oil evaporates and condenses at a number of different temperatures

heated crude oil pipes in at the bottom
vaporised oil rises up the column and fractions are constantly tapped off at different levels where they condense

Question 4

filtration method

Answer 4

filter solution with filter paper to separate precipitate and solution

Question 5

crystallisation method for soluble salts

Answer 5

first warm solution in an open container
allow solvent to evaporate
allow solution to cool
solid will come out of solution and crystals will grow
collect crystals and allow to dry

Question 6

paper chromatography method

Answer 6

separate mixtures and give information to help identify substances
involved a stationary phase and mobile phase
separation depends on distribution of substances between phases

Question 7

Rf value equation

Answer 7

Rf value = distance moved by substance / distance moved by solvent

Question 8

what should pure and impure substances have in chromatography

Answer 8

will only have only one spot on a chromatogram
impure substances will have more than one spot

Question 9

If a substance is more soluble in chromatography what happens

Answer 9

It travels further up the paper

Question 10

how to make potable water

Answer 10

solidification
filtration
chlorination

Question 11

what is solidification

Answer 11

removed ions and salts as it precipitates as lumps at the bottom

Question 12

what’s filtration

Answer 12

removes smaller solids as water goes through the sand and gravel to get rid of smaller bits

Question 13

what’s chlorination

Answer 13

kills bacteria in the water