states of matter - simplifying and purifying

Question 1

facts about solids

Answer 1

• strong forces of attraction
• don’t move, stay in there position
• defined shape
• don’t have much energy
• hardly move

Question 2

facts about liquids

Answer 2

• fixed volume but no fixed shape
• some forces of attraction between the particles
• consistently moving with random motion
• hotter = fast they move
• cause liquids to expand

Question 3

facts about gases

Answer 3

• no forces of attraction between particles
• no shape or volume
• constantly moving with random motion
• collide together

Question 4

change between solid to liquid

Answer 4

melting

Question 5

change between liquid to gas

Answer 5

evaporating

Question 6

change between gas to liquid

Answer 6

condensing

Question 7

change between liquid to solid

Answer 7

freezing

Question 8

change between solid to gas

Answer 8

subliming

Question 9

what is a pure substance

Answer 9

single element or compound

Question 10

how to do a simple distillation

Answer 10

1. pour a sample of seawater into distillation flask
2. set up apparatus:
   connect the bottom end of the condenser to a cold tap using rubber tubing
3. run cold water through the condenser to keep it cool
4. gradually heat the distillation flask
5. water vapour passed into the condenser where it cools and condenses
6. eventually you’ll end up with just salt in the flask

Question 11

how to do fractional distillation

Answer 11

1. put mixture in flask
2. attach fractionating column and condenser to flask
3. gradually heat flask - will all evaporate at different times
4. liquid with the lowest boiling point evaporated first
5. when the first liquid has been collected, raise the temp

Question 12

how to do filtration

Answer 12

filter paper into a funnel and pour mixture in

liquid runs through the paper, leaving solid behind

Question 13

what is filtration for

Answer 13

separating insoluble solid from a liquid

Question 14

how do you do crystallisation

Answer 14

1. pour the solution into an evaporating dish and gently heat solution.
2. some of the water will evaporate, and the solution will get more concentrated.
3. once some of the water has evaporated crystals, will start from.
4. remove the dish from the heat and leave solution to cool.
5. the salt should start to form crystals as it becomes insoluble in the cold, highly concentrated solution.
6. filter the crystals out of the solution and leave them in a warm place to dry

Question 15

what are the 2 phases of chromatography

Answer 15

mobile phase - molecules can move
stationary phase - molecules can’t move

Question 16

how to perform chromatography

Answer 16

1. draw a line at the bottom of the paper – this is the baseline.
2. put some of the solvent into a beaker and dip the bottom of the paper into the solvent.
3. Put a watch glass on the top of the beaker to stop any solvent from evaporate in away.
4. The solvent will start to move up the paper and so will the ink from the spot.
5. Remove the paper from the beaker before the Sun reaches the top mark. The distance the solvent has moved in the pencil.

Question 17

how to calculate the Rf value

Answer 17

distance travelled by solute / distance traveled by solvent

Question 18

what is filtration

Answer 18

A wire mesh, greens out large twigs and then gravel and sand bed filter out any other solid bits

Question 19

what is sedimentation

Answer 19

Iron sulphate aluminium sulphate added to the water, which makes fine particles come together and settle at the bottom

Question 20

what is chlorination

Answer 20

chlorine gas is bubbled through to kill, harmful bacteria in other microbes