Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry 9-1 iGCSE Oxford AQA > Chemical Changes & Metals > Flashcards

Chemical Changes & Metals Flashcards

1
Q

How reactivity determined for metals?

A

Reactivity is determined how easily they lose electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The higher up a metal is in the reactivity series means…

A

The more easily it’ll form positive ions (and the more easily it’ll react with water or acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What happens when metals react with water or an acid?

A

They lose electrons and form positive ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Metals below hydrogen in the reactivity series will…

A

Not react with acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Metals above hydrogen in the reactivity series will…

A

React with acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can metals that are less reactive than carbon be extracted from their ores?

A

By reduction with carbon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How can metals that are more reactive than carbon be extracted from their ores?

A

Using electrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Recite the reactivity series

A

Potassium

Sodium

Lithium

Calcium

Magnesium

Carbon

Zinc

Iron

Hydrogen

Copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Acid + Metal →

A

Salt + Hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Metal + Water →

A

Metal Hydroxide + Hydrogen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How will very reactive metals (potassium, sodium, lithium, calcium) react with acid?

A

They’ll react explosively

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How will less reactive metals (magnesium, zinc, iron) react with acid?

A

Less violently (than very reactive materials)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Will copper react with cold, dilute acid?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The more reactive metal is, the ____ the reaction will go

A

faster

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the speed of reaction (metal + acid) indicated by?

A

Rate of the bubbles of hydrogen given off

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What metals will react with water?

A

Reactive metals like potassium, sodium, lithium & calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What metals will not react with water?

A

Less reactive metals like zinc, iron & copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does magnesium react with cold, dilute acid?

A

Vigorously and produces a lot of bubbles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does zinc and iron react with cold, dilute acid?

A

Fairly slowly (speed up if heated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How can smelting be used to obtain copper?

A

Heat copper ores in a furnace to extract high concentrations of copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is an advantage of smelting?

A

Get large amounts of copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is a disadvantage of smelting?

A

Time consuming

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How can bioleaching be used to obtain metal?

A

Uses bacteria to produce leachate solutions that contain metal compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is an advantage of bioleaching?

A
  1. More simpler/cheaper to operate/maintain
  2. Environmentally friendly
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is a disadvantage of bioleaching?

A

Very slow (compare to like smelting)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

How can phytomining be used to obtain copper?

A
  1. Crops are planted on soil that contains very small amounts of copper
  2. The plants absorb the copper through their roots
  3. Plants are burnt to ashes to extract copper
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is an advantage of phytomining?

A

Easier to use plants than mining - cheaper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is a disadvantage of phytomining?

A

Metal is poor quality - many impurities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

How can electrolysis be used to obtain copper?

A

Electricity is used to break down copper compounds into copper elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is an advantage of electrolysis?

A

Get pure copper atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is a disadvantage of electrolysis?

A
  1. Takes a lot of electricity
  2. Expensive
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is an alloy?

A

Mixture of at least two elements, where at least one of these is a metal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How are the atoms arranged in a metal?

A

There are layers of metal atoms which can move easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

How are the atoms arranged in an alloy?

A

Layers of atoms in alloys are disrupted so they don’t move easily

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

How are alloys made?

A

By adding another element to a metal = disrupts structure of metal, making alloys harder than pure metals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Acid + Metal Carbonate →

A

Salt + Water + Carbon Dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is thermal decomposition?

A

When heat is used to break substances down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

Do all carbonates of metals in Group 1 decompose at temperatures reached by a Bunsen burner?

A

No

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Why aren’t most metals found in earth in their pure forms?

A

They’re fairly reactive so they’re found as compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is an ore?

A

A type of rock that contains metal compounds

41
Q

What are native metals?

A

Metals are so unreactive that they’re found in their elemental form (silver, gold)

42
Q

What is oxidation?

A

Gain of Oxygen

43
Q

What is reduction?

A

Loss of Oxygen

44
Q

Why can only metals below carbon in the reactivity series be extracted by reduction using carbon?

A

Because carbon can only take oxygen away from metals which are less reactive than it

45
Q

What does OIL RIG stand for?

A

Oxidation is Loss, Reduction is Gain

46
Q

What is REDOX?

A

REDuction and OXidation happen at the same time

47
Q

Write the 2 half ionic equations & the ionic equation for when chorine reacts with potassium bromide solution (halogens)

48
Q

Write the 2 half ionic equations & the ionic equation for when iron reacts with dilute sulfuric acid

49
Q

What is a displacement reaction?

A

When a more reactive metal replaces a less reactive metal from its compound

50
Q

In a displacement reaction, what happens to the metal ions?

A

Gain electrons and are reduced

51
Q

In a displacement reaction, what happens to the metal atoms?

A

Loses electrons and is oxidised

52
Q

What is are metal displacement reactions essentially?

A

Redox reactions

53
Q

What is electrolysis?

A

Passing electric current through molten/dissolved ionic substances to break them down into elements

54
Q

What is an electrolyte?

A

Molten or dissolved ionic compound (so ions are free)

55
Q

Explain the electrolysis process

A
  1. Electric current passes through electrolyte
  2. Ions move towards electrodes - where they react = compound decomposes
    1. Negative ions in electrolyte will move towards anode (+ve electrode) & lose electrons (they’re oxidised) = form uncharged element
    2. Positive ions in electrolyte will move towards cathode (-ve electrode) & gain electrons (they’re reduced) = form uncharged element
  3. This creates flow of charge through electrolyte as ions travel to electrodes
56
Q

Why can’t an ionic solid be electrolysed?

A

Ions in fixed positions - can’t move

57
Q

Why can we electrolyse molten ionic compounds?

A

Electrolysed bc ions can move freely + conduct electricity

58
Q

What type of material are electrodes made from and why?

A

From inert material = don’t react with electrolyte

59
Q

Molten ionic compounds are always…

A

broken up into their elements

60
Q

Explain how aluminium is extracted from its ore

A
  1. Aluminium is extracted from ore bauxite by electrolysis
  2. Aluminium oxide = very high melting temperature ∴ mixed with cryolite to lower melting point
  3. Molten mixture contains free ions - conduct electricity
  4. Positive Al3+ ions attracted to negative electrode, where they pick up 3 electrons & turn into neutral aluminium atoms → sink to bottom of electrolysis tank
  5. Negative O2- ions are attracted to positive electrode, where they each lose two electrons → neutral oxygen atoms then combine to form O2 molecules
61
Q

Why does the anode need to regularly replaced when extracting aluminium from its ore?

A

Made from carbon = regularly reacts with oxygen to produce carbon dioxide

62
Q

What is the ionic half equation at the negative electrode? (aluminium extraction)

A

Al3+ + 3e- → Al

63
Q

What is the ionic half equation at the positive electrode? (aluminium extraction)

A

2O2- → O2 + 4e-

64
Q

What is word equation for aluminium extraction?

A

Aluminum oxide → aluminium + oxygen

65
Q

What is symbol equation for aluminium extraction?

A

2Al2O3(l) → 4Al(l) + 3O2(g)

66
Q

Name 3 energy costs of extracting aluminium

A
  1. Bauxite purification
  2. Aluminum ore has to be minded
  3. Extracting aluminium
  4. Carbon anodes are replaced regularly
67
Q

Name 3 environmental costs of extracting aluminium

A
  1. Fuels used to keep aluminium hot
  2. Make CO2 because carbon is used for anode
  3. Electricity is used
68
Q

What is brine?

A

Solution of sodium chloride & water

69
Q

What does the electrolysis of brine produce?

A

Chorine, hydrogen and sodium hydroxide

70
Q

Name 3 uses of chlorine

A
  1. Disinfectant and purifier
  2. Manufacture of hydrochloric acid
  3. Making plastics
71
Q

Name 2 uses of hydrogen

A
  1. Manufacture of hydrochloric acid
  2. Potential as a pollution-free fuel
72
Q

Name 4 uses of sodium hydroxide

A
  1. Removing pollutants from water
  2. Processing food products
  3. Manufacture of paper
  4. Soap production
73
Q

Where is the object being electroplated made?

A

At the cathode (in an electrolysis cell)

74
Q

Where is the plating metal made (electroplating)?

A

At the anode

75
Q

When electroplating, what does the electrolyte contain?

A

Contains ions of plating metal

76
Q

When electroplating, at the anode (made of zinc), what happens?

A
  1. Zinc atoms in electrode are oxidised
  2. Lose 2 electrons each & form zinc ions
  3. Which leave anode and go into solution
77
Q

When electroplating, at the anode (made of zinc), what is the half ionic equation?

A

Zn(s) → Zn2+(aq) + 2e-

78
Q

When electroplating, at the cathode (where copper foil is to be plated), what happens?

A
  1. Zinc ions from solution are reduced
  2. Gain 2 electrons & form zinc atoms
  3. Which are deposited on copper cathode
79
Q

When electroplating, at the cathode (where copper foil is to be plated), what is the half ionic equation?

A

Zn2+ (aq) + 2e- → Zn(s)

80
Q

Why are objects electroplated? (name 3 reasons)

A
  1. To improve their appearance
  2. To protect their surface
  3. To use smaller amounts of precious material
81
Q

Electrolysis: What ions are there in aqueous solutions?

A
  1. Hydrogen ions (H+) and hydroxide ions (OH-) from water
  2. Ions from ionic compound
82
Q

Electrolysis of Aqueous Solutions: Which ions are discharged at electrodes when solution is electrolysed depends on…

A

relative reactivity of all ion in solution

83
Q

Electrolysis of Aqueous Solutions: At the cathode, if H+ ions & metal ions are present…

A

Hydrogen gas will be produced if metal ions form elemental metal that’s more reactive than hydrogen

84
Q

Electrolysis of Aqueous Solutions: At the cathode, if metal ions form element metal that’s less reactive than hydrogen…

A

Solid layer of pure metal will be produced instead which coats cathode

85
Q

Electrolysis of Aqueous Solutions: At the anode, if OH- and halide ions are present…

A

Molecules of chlorine, bromine or iodine formed

86
Q

Electrolysis of Aqueous Solutions: At the anode, if no halide ions are present…

A

OH- ions discharged and oxygen formed

87
Q

Electrolysis of Copper Sulfate Solution: Why does copper coat the cathode?

A

Because copper is less reactive than hydrogen so at the cathode it’s produced

88
Q

Electrolysis of Copper Sulfate Solution: Why are oxygen and water produced at the anode?

A

No halide ions present

89
Q

Electrolysis of Copper Sulfate Solution: What is the half ionic equation at the cathode?

A

Cu2+ + 2e- → Cu

90
Q

Electrolysis of Copper Sulfate Solution: What is the half ionic equation at the anode?

A

4OH- → O2 + 2H2O + 4e-

91
Q

Electrolysis of Sodium Chloride Solution: Why is hydrogen gas produced at the cathode?

A

Sodium metal is more reactive than hydrogen

92
Q

Electrolysis of Sodium Chloride Solution: Why is chlorine gas produced at the anode?

A

Chloride ions are present in the solution

93
Q

Electrolysis of Sodium Chloride Solution: What is the half ionic equation at the cathode?

A

2H+ + 2e- → H2

94
Q

Electrolysis of Sodium Chloride Solution: What is the half ionic equation at the anode?

A

2Cl- → Cl2 + 2e-

95
Q

What does cryolite do to aluminium oxide?

A

Lowers its melting point?

96
Q

How does cryolite lower aluminium oxide’s melting point?

A

Weakens attractions in aluminium oxide

97
Q

Explain how carbon dioxide is produced at the anode during the electrolysis of aluminium oxide (4 marks)

A
  • Oxide/O2- ions attracted to anode
  • Oxygen gas is produced
  • Anodes made from carbon
  • Carbon reacts with oxygen to produce CO2
98
Q

What does (aq) - aqueous mean?

A

Dissolved in water

99
Q

Electrolysis of Aqueous Solutions: Why do you get H+ and OH- ions?

A

Bc water molecules ionise (spilt), forming them

Chemistry 9-1 iGCSE Oxford AQA (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions