matter - structures and properties

Question 1

what does time measure

Answer 1

how long it takes for something to happen

Question 2

SI unit for time

Answer 2

seconds

common units: min, hour

Question 3

what does temperature measure

Answer 3

how hot or cold something is

Question 4

SI unit for temperature

Answer 4

K (kelvin)

common units: celsius

Question 5

what does length measure

Answer 5

the distance between 2 points

Question 6

SI unit for length

Answer 6

(m)metre

common units: cm, km

Question 7

what does mass measure

Answer 7

how much matter is present in a substance

Question 8

instrument to measure mass

Answer 8

• electronic balance
• beam balance

Question 9

SI unit for mass

Answer 9

(kg) kilograms

common units: grams, tonnes

Question 10

1 tonnes =

Answer 10

1000kg = 1000000g

Question 11

what does volume measure

Answer 11

how much space somthing occupies

Question 12

SI unit for volume

Answer 12

(m³) cubic metre

common unit: cm³, dm³

Question 13

how many dp for burette, pipette and volumetric flask

Answer 13

2

Question 14

how many dp for measuring cylinder

Answer 14

1

Question 15

where to read the volume

Answer 15

bottom of meniscus

Question 16

criteria for gas collection

Answer 16

• solubility of water
• density of gas

Question 17

how to collect gas

Answer 17

gas syringe

(collect small and accurate volumes of gas)

Question 18

methods for collecting gas

Answer 18

• water displacement
• downward delivery
• upward delivery

Question 19

criteria for using water displacement to collect gas

Answer 19

insoluble in water

Question 20

criteria for using downward delivery when collecting gas

Answer 20

denser than surrounding air

Question 21

criteria for using upward delivery when collecting gas

Answer 21

less dense than surrounding air

Question 22

examples of how to dry gas

Answer 22

• concentrated sulfuric acid
• quicklime (calcium oxide)
• fused calcium chloride

Question 23

types of mixtures

Answer 23

• solid-soild mixture
• solid-liquid mixture
• liquid-liquid mixture

Question 24

how to separate solid-solid mixtures

Answer 24

• magnetic attraction
• sieving
• using suitable solvents
• sublimation

Question 25

what is the purpose of using magnetic attraction

Answer 25

use magnet to separate magnetic solids from non-magnetic solids

Question 26

what is the purpose of using a sieve

Answer 26

separate solids with different particle sizes

Question 27

what is needed when using a sieve

Answer 27

a sieve with suitable pore size

Question 28

what is the purpose of using suitable solvents

Answer 28

separate solid-solid mixtures in which only one of the solids is soluble in the solvent

Question 29

how to use suitable solvent

Answer 29

add solvent to disolve one solid

Question 30

what is the purpose of using sublimation

Answer 30

separate a substance that changes from the solid to gaseous state directly

Question 31

substances that can sublime

Answer 31

- dry ice - iodine - ammonium chloride

Question 32

how to separate solid-liquid mixture

Answer 32

- filtration - evaporation to dryness - crystallisation - simple distillation

Question 33

what is the purpose of using filtration

Answer 33

separate insoluble solids from liquids

Question 34

working principle for filtration

Answer 34

- particle size - pore size of filter paper

Question 35

what is the filtrate

Answer 35

liquid that passes through the filter

Question 36

what is residue

Answer 36

solid that remains on the filter

Question 37

what is the purpose of crystallisation

Answer 37

used to obtain a pure solid from its saturated solution

Question 38

what is saturated solution

Answer 38

no more solute can be dissolved

Question 39

what is the difference between evaporation to dryness and crystallisation

Answer 39

- evaporation to dryness is heated until there is no more solvent - crystallisation is heated until a saturated solution is formed

Question 40

when to use evaporation to dryness

Answer 40

solid that does not decompose

Question 41

when to use crystallisation

Answer 41

solid that decompose

Question 42

purpose of simple distillation

Answer 42

used to separate a pure solvent from a solution

Question 43

what is distillate

Answer 43

pure substance that is collected after distillation

Question 44

position of thermometer bulb

Answer 44

junction before entering the condenser

Question 45

function of condenser

Answer 45

cool and condense hot vapour into liquid

Question 46

direction of water entering condenser

Answer 46

bottom in top out

Question 47

purpose of boiling chips

Answer 47

ensure smooth boiling

Question 48

how to separate liquid liquid mixtures

Answer 48

- separating funnel - chromatography - fractional distillisation

Question 49

what is miscible liquid

Answer 49

liquids that can mix | (homogeneous mixture)

Question 50

what is immiscible liquid

Answer 50

liquids that cannot mix | (heterogeneous mixture)

Question 51

what separating technique can separate immiscible liquids

Answer 51

separating funnel

Question 52

purpose of separating funnel

Answer 52

separate immiscible liquids with different density

Question 53

what separating technique can separate miscible liquids

Answer 53

fractional distillation

Question 54

purpose of fractional distillation

Answer 54

separate miscible liquids with different boiling points

Question 55

what does fractional distillation have that simple distillation does not

Answer 55

- fractionating column - glass beads

Question 56

purpose of chromatography

Answer 56

separate a mixture of substances which have different solubilities in a given solvent

Question 57

when to use locating agent

Answer 57

colourless samples

Question 58

purpose of locating agents

Answer 58

locate the spots on the chromatogram by making it visible

Question 59

explain what is meant by Rf value of a sample

Answer 59

Rf value of a substance is a measure of its solubility in the solvent

Question 60

how to measure Rf value

Answer 60

distance travelled by solute/distance travelled by solvent

Question 61

what are important things to take note of during chromatography

Answer 61

- starting line drawn in pencil - solvent level below starting line - sample spot should be small and not too close

Question 62

why does starting line need to be drawn in pencil

Answer 62

insoluble in solvent and will not interfere with the results

Question 63

why does the solvent level need to be below starting line

Answer 63

prevent sample from dissolving before separating

Question 64

why does the sample spot have to be small and not too close

Answer 64

ensure clear separating and prevents overlap

Question 65

what is the solvent front

Answer 65

the distance travelled by the solvent

Question 66

the greatest the distance

Answer 66

- the larger the Rf value - more soluble in solvent

Question 67

test for purity

Answer 67

heat substance to melt/boil it, if melting/boiling point is fixed, it is pure substance