Topic 2 Flashcards

1
Q

2.1
Describe the properties of a solid

(Hint: arrangement, movement, relative energy, volume, closeness, compressed?)

A

-Arranged in a regular, fixed pattern
-Vibrate around fixed point
-Low energy
-Fixed volume
-Very close together
-Can’t be compressed

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2
Q

2.1
Describe the properties of a liquid

(Hint: arrangement, movement, relative energy, volume, closeness, compressed?)

A

-Randomly arranged
-Can move freely
-Greater energy than solids
-Fixed volume
-Close together
-Can’t be compressed

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3
Q

2.1
Describe the properties of a gas

(Hint: arrangement, movement, relative energy, volume, closeness, compressed?)

A

-Randomly arranged
-Can move freely
-Lot of energy
-Don’t have fixed volume
-Lots of space between particles
-Can be compressed

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4
Q

2.2
Name the interconversion from solid to liquid

A

Melting

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5
Q

2.2
Name the interconversion from liquid to gas

A

Evaporation

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6
Q

2.2
Name the interconversion from gas to liquid

A

Condensation

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7
Q

2.2
Name the interconversion from liquid to solid

A

Freezing

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8
Q

2.2
Name the interconversion from solid to gas

A

Sublimation

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9
Q

2.2
Name the interconversion from gas to solid

A

Deposition/Reverse sublimation

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10
Q

2.2
What type of changes are interconversions between states of matter

A

Physical changes

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11
Q

2.2
What is a physical change?

A

-Reversible
-Change in state
-Change in arrangement
-Chemical properties don’t change
-No new material

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12
Q

2.2
What is a chemical change?

A

-Irreversible
-Chemical properties change
-New material formed

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13
Q

2.2
What 4 things can be seen while a chemical change is taking place?

A

-Colour change
-Heat/light given off (Temperature change)
-Precipitate
-Effervescence

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14
Q

2.2
Which change (physical or chemical) is irreversible? Why?

A

-Chemical
-Chemical compounds formed
-You’d have to pull apart molecules and rebuild in original form - difficult

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15
Q

2.2
Is dissolving tablets in water a physical or chemical change? Is it reversible or irreversible?

A

-Physical
-Reversible

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16
Q

2.2
Is a bunsen burner burning gas a physical or chemical change? Is it reversible or irreversible?

A

-Chemical
-Irreversible

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17
Q

2.2
Is a magnesium dropped in an acid a physical or chemical change? Is it reversible or irreversible?

A

-Chemical
-Irreversible

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18
Q

2.3
Explain the conversion from a solid into a liquid

A

-When heated -> particles gain KE -> vibrate more around fixed point
-Intermolecular bonds separate
-F of attraction holding particles together overcome -> particles spread apart
-Move faster (more KE)

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19
Q

2.3
Explain the conversion from a liquid to a solid

A

-When cooled -> particles move less bc decreased KE
-Intermolecular bonds form

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20
Q

2.4
State the melting and boiling point for water

A

Mp - 0°
Bp - 100°

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21
Q

Define the term fixed (arrangement)

A

Can’t move around

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22
Q

Define the term regular (arrangement)

A

Clear pattern

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23
Q

2.4
Ethanol has a mp of -114°C and a bp of 78°C. Predict what state of matter it will be at the following temperatures:
-250
-100
0
25
250
You may draw a number line to help

A

-250 = Solid
-100 = Liquid
0 = Liquid
25 = Liquid
250 = Gas

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24
Q

Define the term compound

A

2 or more different types of elements chemically joined together

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25
Q

Define the term element

A

Substance made up of only 1 type of atom

26
Q

Define the term molecule

A

2 or more atoms chemically joined together

27
Q

Define the term mixture

A

-2 or more diff. elements NOT chemically joined together
-Easily separated

28
Q

2.5
What is a pure substance?

A

Contains only 1 element or compound

29
Q

2.5
True or false: Air is pure
Why?

A

-False
-Contains carbon dioxide, oxygen, nitrogen…
-Compounds not chemically joined with each other
-So it is a mixture

30
Q

2.6
Why does the temperature of the heating curve of a pure substance stay constant when it is changing state?

A

All KE being used to overcome IM bonds

31
Q

2.6
Sketch a diagram to show what a heating curve for a pure substance would look like

A

Replace heat added with energy added. Add bp and mp on straight lines. Ignore the 4 labels.

https://www.google.com/search?q=heating+curve+gcse&tbm=isch&ved=2ahUKEwif3fXcueX-AhW5rycCHegTCLoQ2-cCegQIABAA&oq=heating+curve+gcse&gs_lcp=CgNpbWcQAzIFCAAQgAQ6BwgAEIoFEENQvg9Y6hpggRxoAHAAeACAAYQCiAHfB5IBBTAuMi4zmAEAoAEBqgELZ3dzLXdpei1pbWfAAQE&sclient=img&ei=jMZYZJ_nHrnfnsEP6Keg0As&bih=629&biw=1300&rlz=1CAOBDQ_enGB939&safe=active&ssui=on#imgrc=iMm0b6QssSsooM&imgdii=xZHQGRPT60TsHM

32
Q

2.6
Compare the heating curve of pure and impure substances

A

-Pure substances change state at single temperature (sharp melting point)
-Whereas impure substances change state over range of temperatures

33
Q

2.7
What do simple and fractional distillation separate?

A

Mixture of solutions

34
Q

2.7
Explain how simple distillation works

A

-Heat solution to temp. of liquid with lowest bp (Bunsen burner)
-Liquid evaporates up tube -> condenser condenses vapour to liquid
-Collected in beaker
-Other liquid still in flask

35
Q

2.7
What are the risks when carrying out simple distillation? How can you prevent them?

A

-Shattering glass (suck back), take delivery tube out whilst still heating & wear goggles
-Burning rubber = carcinogens (cancer causing fumes), keep rubber away from heat
-Burning lanyard/hair, take off & tie up

36
Q

2.7
You want to separate three liquids. Explain how you can use fractional distillation to do this

A

-Heat solution to temp of liquid with lowest bp (Bunsen burner)
-Liquid evaporates up fractionating column
-Condenser cools vapour -> liquid collected in beaker
-Other liquid may evaporate -> cold glass rods condense back into liquid (bc are cooler than the bp) iquid falls back into flask
-Raise temp -> repeat for next liquid

37
Q

2.7
What does filtration separate?

A

Insoluble substance from liquid

38
Q

2.7
Explain how filtration works

A

-Pour mixture into filter paper
-Liquid passes through
-Solid can’t

39
Q

2.7
What does crystallisation separate?

A

Soluble substance from liquid

40
Q

2.7
Explain how crystallisation works

A

-Heat solution in evaporating basin -> evaporates water
-Crystals left behind

41
Q

2.7
Why should you be careful when heating a solution in crystallisation?

A

-Heating could affect chemical trying to crystalise
-Some chemicals break down when heated

42
Q

2.7
What is the stationary phase in paper chromatography? Why?

A

-The paper
-Because it does not move

43
Q

2.7
What is the mobile phase in paper chromatography? Why?

A

-The solvent
-Because it moves

44
Q

2.9
What does chromatography separate?

A

Mixture of soluble substances e.g dye, ink

45
Q

2.9
Explain how to carry out chromatography

A

-Pencil line at bottom of filter paper
-Space out dots of each sample on line
-Bottom of paper into solvent (solvent reach just below pencil line)
-Travels up paper -> dissolves inks
-Inks also travel up paper at different rates

46
Q

2.10a
In chromatography, how can you tell whether a substance is pure or impure?

A

Pure = Single dots in all solvents
Impure = Multiple dots

47
Q

2.10c
State the formula used to calculate the Rf value.
How can you check your answer?

A

-Rf= Distance travelled by dye/Distance travelled by solvent
-Ans always between 0-1

48
Q

2.10c
What does a larger Rf value mean?

A

More soluble

49
Q

Define the term solvent

A

Able to dissolve other substances

50
Q

Define the term solute

A

Can be dissolved in a solvent

51
Q

Define the term solution

A

Mixture formed when solute is dissolved in solvent

52
Q

Define the term soluble

A

Can be dissolved

53
Q

Define the term insoluble

A

Can not be dissolved

54
Q

2.12a
Define the term potable

A

Drinkable

55
Q

2.12a
What are the stages involved in treating water in order to make it potable?

A

-Sedimentation
-Filtration
-Chlorination

56
Q

2.12a
Describe what happens in sedimentation when treating water

A

Sediments sink to bottom of reservoir

57
Q

2.12a
Describe what happens in filtration when treating water

A

-Dirty water travels through sand & water
-Sediments get stuck
-Water goes through

58
Q

2.12a
Describe what happens in chlorination when treating water

A

Chlorine added to water to kill bacteria & micro-organisms

59
Q

2.12b
Describe how sea water can be made potable using simple distillation

A

-Water evaporates to form water vapour
-Salt left in beaker
-Water vapour condenses to form pure water

60
Q

2.12c
Why must distilled water be used for chemical analysis?

A

-Is pure
-Tap water contains dissolved salts -> interfere w/ results
-Incorrect results will be obtained