states of matter

Question 1

whats the process called to get a solid to a liquid

Answer 1

melting

Question 2

liquid to gas

Answer 2

evaporating/boiling

Question 3

gas to liquid

Answer 3

condensing

Question 4

liquid to solid

Answer 4

freezing

Question 5

gas to solid

Answer 5

desposition

Question 6

solid to gas

Answer 6

sublimation

Question 7

name 5 characteristics of solids

Answer 7

strong, definite shape, regular arrangement of particles, cant be compressed, definite volume, very dense, strong attractive forces, little particle movement, particles in fixed position

Question 8

name 5 characteristics of liquids

Answer 8

little strength, no definite shape, random arrangement of particles, cant be compressed, definite volume, constant random motion, particles free to move, quite dense, weaker attractive forces

Question 9

name 5 characteristics of a gas

Answer 9

no strength, no definite shape, random arrangement of particles, can be compressed, no definite volume, constant rapid and random motion, particles free to move, low density, no forces of attraction

Question 10

what do solid and liquid particles have in common

Answer 10

they both cant be compressed, have a definite volume,

Question 11

what do liquid and gas particles have in common

Answer 11

no definite shape, random arrangement of particles, particles free to move

Question 12

what do solid and gas particles have in common

Answer 12

nothingggg

Question 13

what happens during chemical reactions

Answer 13

bonds between atoms break and the atoms change places

Question 14

what does pure mean

Answer 14

made up of a single element or compound

Question 15

what is a mixture

Answer 15

if you have got more than one compound present or different element that aren’t part of a single compound

Question 16

what does every pure substance have

Answer 16

a sharp melting and boiling point

Question 17

what will impure substances have

Answer 17

it will melt/boil over a range of temperatures

Question 18

what is simple distillation used for

Answer 18

separating a liquid from a solution

Question 19

how would you carry out simple distillation

Answer 19

1 - pour your mixture into a distillation flask
2- put distillation flask on top of bunson burner. at the end of the condensing tube put a jug for the substance to go into
3-heat the mixture
4-the vapour passes through the condenser where it coolsand condenses back to a liquid and goes into the jug where it is collected

Question 20

what is the problem with simple distillation

Answer 20

you can only use it to separate substances with very different boiling points

Question 21

what is fractional distillation used for

Answer 21

separating a mixture of liquids

Question 22

how would you carry out fractional distillation

Answer 22

1-put mixture in flask. attach a fractioning columnand condenser above the flask
2-heat the flask. the liquids will have different boiling temperatures so will evaporate at different times
3-liquids with lower boiling points evaporate first when the thermometer shows the temperature
4-liquids with higher boiling points might also start to evaporate

Question 23

what is the last stage of fractional distillation

Answer 23

5- when the first liquid has been collected raise the temperature until the next one reaches the top

Question 24

what is filtration used for

Answer 24

used to separate insoluble solid from a liquid

Question 25

how would you carry out filtration

Answer 25

put some filter paper into a funnel and pour your mixture into it

Question 26

what is crystallistaion used for

Answer 26

to separate a soluble solid from a solution

Question 27

how would you carry out crystallisation

Answer 27

1-pour solution into evaporating dish and heat 2-when you see crystals start to form romove dish from heat and leave it to cool 3-it should start to form crystals as it becomes insoluble in the cold. 4- filter the crystals out of the solution and leave them to dry

Question 28

what is chromatography used for

Answer 28

a method of separating a mixture of soluble substances and identifyimg them

Question 29

what are the 2 phases of chromotography

Answer 29

mobile phase - when the molecules can move | stationary phase - when the molecules csnt move

Question 30

how would you carry out a chromatography experiment

Answer 30

1- draw a pencil line near the bottom of the paper. this is the baseline. put a spot of the mixture that needs ro be separated on the line 2-put some solvent into the beaker and dip the bottom of the paper into the solvent but not the spot 3-put a watch glass on top of the paper to stop the solvent from evaporating 4-the solvent will move up the paper and so ill the mixture when it dissolves. 5-you will see different chemicals from the sample separate out forming spots at different places on the paper 6-remove paper from beaker before it gets to the top . mark the distance the solvent has moved (the solvent front)

Question 31

what is an Rf value

Answer 31

the ratio between the distance travelled by the substance and the distance travelled by the solvent

Question 32

what is the Rf formula

Answer 32

distance travelled by solute Rf=------------------------------------------------- distance travelled by solvent

Question 33

how do you find the distance travelled by the solute

Answer 33

measure from the baseline to the centre of the spot

Question 34

Why is chromatography used

Answer 34

To see if a substance is present in a mixture

Question 35

Where do we get our potable water from

Answer 35

Surface water,ground water and waste water

Question 36

Where do you get surface water from

Answer 36

Lakes, rivers and reservoir

Question 37

Where do you get ground water from

Answer 37

Aquifers (rocks that trap that water underground)

Question 38

What are the three stages of water treatment

Answer 38

Filtration - a wire mash screens out large twigs and then gravel and bits of sand Sedimentation- iron surface or aluminium sulfate is added, this makes fine particles clump together and settle at the bottom Chlorination - chlorine is added to kill harmful bacteria

Question 39

What can you distill to get potable water

Answer 39

Sea water

Question 40

What type of water should you use in a chemical analysis

Answer 40

Pure water