MATTER

Question 1

diffusion?

Answer 1

net movement of particles from a region of higher concentration to an area of lower concentration.

Question 2

how to increase diffusion rate

Answer 2

increase temperature
increase concentration gradient
decrease molecular mass

Question 3

element

Answer 3

chemical substance that cannot be broken down further

Question 4

compound

Answer 4

formed when two or more elements are chemically bonded in a fixed ratio. the elements lose their individual chemical properties after being bonded.

ex. FeS is not magnetic

Question 5

mixture

Answer 5

made up of two or more substances that are not chemically bonded. the substances don’t lose their individual chemical properties.

Question 6

homogenous mixture

Answer 6

• has a uniform composition throughout

ex. alloy - mixture of two or more metals and sometimes non-metals as well. (steel, stainless steel, brass)

Question 7

heterogenous mixture

Answer 7

• does not have a uniform composition throughout

ex. sand with water

Question 8

emulsifier

Answer 8

substance that stabilizes emulsions

Question 9

dispersed phase

Answer 9

suspended particles

Question 10

continuous phase

Answer 10

medium of suspension/dispersion medium

Question 11

emulsion

Answer 11

• a type of colloid.
• liquid+liquid (immiscible or partly miscible)

Question 12

how to separate a colloid?

Answer 12

centrifugation

Question 13

apparatus for the measurement of time, temperature, mass, and volume

Answer 13

stopwatch, thermometer, electronic balance, and graduated cylinder

Question 14

boiling vs evaporation

Answer 14

• boiling = fast
• evaporation = slow

evaporation = surface phenomenon, has cooling effect

• evaporation may occur at any temperature above freezing point, while boiling occurs only at the substance’s boiling point
• lots of bubbles in boiling, none in evaporation because it happens only at the surface

bubbles form because dissolved gases escape the liquid, since evaporation only on surface this wont be applicable

Question 15

contents of fractional distillation of crude oil

Answer 15

1. petroleum gas
2. fuel oil
3. lubricating oil
4. petrol
5. kerosene
6. diesel
7. bitumen

Question 16

physical change

Answer 16

physical change alters appearance or state of the substance w/o changing chemical composition. (no new product is formed)

Question 17

chemical change

Answer 17

chemical changes result in the production of a new substance and cannot be reversed.

Question 18

phsyical vs chemical change

Answer 18

physical change - reversible or irreversible (no new product formed)
chemical change - irreversible (new product formed)

Question 19

suspension

Answer 19

heterogeneous mixture where solid particles do not dissolve in a liquid solution
* particles settle over time and can be filtered out

Question 20

colloid

Answer 20

• heterogeneous mixture where dispersed particles remain evenly suspended in a continuous phase
• particles are larger than solution, and smaller suspension (medium particle size)
• particles do not settle over time

ex. paint, milk, fog

Question 21

solution

Answer 21

homogeneous mixture of one or more solutes dissolved in a solvent

Question 22

melting

Answer 22

solid-liquid

Question 23

freezing

Answer 23

liquid-solid

Question 24

vaporization

Answer 24

liquid-gas

1. evaporation
2. boiling

Question 25

condensation

Answer 25

gas-liquid

Question 26

sublimation

Answer 26

solid-gas

Question 27

deposition

Answer 27

gas-solid

Question 28

macroscopic properties of solids

Answer 28

* high density * fixed volume * fixed shape * not compressible

Question 29

microscopic properties of solids

Answer 29

- intermolecular force of attaction very high - intermolecular space very low (particles extremely close together)-

Question 30

macroscopic properties of liquids

Answer 30

- fixed volume - shape not fixed, fills the container its put in - partially compressible

Question 31

micrscopic properties of liquids

Answer 31

- intermolecular force of attraction weaker than solids, stronger than gas - intermolecular space higher than solids, lowr than gas -

Question 32

motion of particles in solids

Answer 32

vibrate in fixed positions

Question 33

motion of partciles in liqiuds

Answer 33

fibrate, rotate, and translate. this allows the liquid to flow.

Question 34

macroscopic propties of gases

Answer 34

- volume = not fixed - shape = not fixed - compressible = yes

Question 35

microscopic peropties of gases

Answer 35

- weak intermollcular force of atrraction - high intermolcuar space

Question 36

motion of particles in gas

Answer 36

vibrate, rotate, and translate to a greater extent than liquids (high energy motion). this allows gases to flow.

Question 37

kinetic theory

Answer 37

all matter is made up of small particles that are in constant random motion

Question 38

matter

Answer 38

anythign that occupies space and has mass - 3 states 1. solid 2. liqiud 3. gas

Question 39

saturated solution

Answer 39

sol contains max amt of solute that can dissolve in the solvent at a given temp ## Footnote if more solute added it will settle down

Question 40

unsaturated solution

Answer 40

contains less than max amt of solute that can be dissolved in a solvent at a given temp

Question 41

supersaturated solution

Answer 41

contains more than max amt of solute that can be dissolved in a solvent at a given temp - unstable, and will begin to crystallize

Question 42

to increase saturation point

Answer 42

increase temp of solution

Question 43

distillation

Answer 43

* used to seperate liquids with >25 C difference in bp or a solvent from solution * thermometer * round btotom flask, heat * it evaporates goes in condensor wear cool water out and in so it ocndenses on surface * pure substnace collected as distilate

Question 44

fractional distillation

Answer 44

- uses fractionating column (extra, rest same) - to seperate liquid liquid mixture with close boiling piints (<25C apart) - ex. crude oil

Question 45

seperating funnel

Answer 45

used to seperate immiscible liquids based on density differences (like oil & water) by allowing them to form distict layers so that they can be drained seperately

Question 46

# by all filter paper/funnel

Answer 46

* solid particles from liquid get stuck in filter paper as residue * filtrate passes through * process repeated mulitple times to ensure completely clean

Question 47

decantation

Answer 47

- in suspension when solid settles down - pour liquid out from top, solid remains down

Question 48

evaporation (method of seperation)

Answer 48

- typically used w/ water - liquid turns into vapour, leaving behind the solute

Question 49

# as a method of seperation sublimation

Answer 49

- if two substances there - one sublime other isnt - so as you heat one will turn directly to gas - so non sublime impuriy left behind

Question 50

magnetic seperation

Answer 50

- two substances there - one magnetic - one not - bring magnet close - magnetic substance gets attracted - leavs non-magnetic behind

Question 51

chromatography

Answer 51

- separates components of a mixture based on their differing rates of movement through a stationary phase under the influence of a mobile phase. - used extensively for analysis and purification. (ex. foostuff, drugs)

Question 52

rf value

Answer 52

distance travelled by solute/distance travelled by solvent

Question 53

if more distance travelled by the spot

Answer 53

more soluble | doesnt move = insoluble

Question 54

higher rf value

Answer 54

more soluble

Question 55

solvent has to be below the ink (spot) why

Answer 55

to avoid mixing

Question 56

why tank covered?

Answer 56

* fumes may be toxic * to avoid evaporation of substances

Question 57

pattern formed on chromatography paper =

Answer 57

chromatogram