C2 - Chemical Resources Flashcards Preview

Chemistry GCSE OCR Gateway B > C2 - Chemical Resources > Flashcards

Flashcards in C2 - Chemical Resources Deck (180):
1

What is the crust?

The Earth's outer layer of solid rock. Average depth of 20km

2

What is the lithosphere?

It includes the crust and upper part of the mantle. It is made up of a jigsaw of tectonic plates and is cold and rigid - over 100km thick in places.

3

What is the mantle?

Solid section between the crust and core. Very rigid and temperature increases. Becomes less rigid and flows very slowly - semi liquid.

4

What is the core?

It is just over half the Earth's radius. 2 parts - inner core (solid) and outer core (liquid).

5

What causes tectonic plates to move?

Radioactive decay creates lots of heat which creates convection currents in the mantle, causing the plates of the lithosphere to move.

6

What are tectonic plates?

Big rocky rafts that float on the mantle because they are less dense. Move very slowly - about 2.5cm per year.

7

What can tectonic plates cause?

Earthquakes and volcanoes where the plates meet, caused by movement of the plates against each other.

8

Why is it difficult to study the Earth's inner structure?

The crust is too thick to drill through.

9

How can scientists study the Earth's structure?

Using seismic waves produced by earthquakes or man made explosions. Measure the time it takes for them to travel through the Earth and where they are detected.

10

What are the two types of seismic wave?

P-Waves which can only travel through solids and liquids. S-Waves can only travel through solids.

11

How are volcanoes formed?

As an oceanic plate is forced down, it melts and starts to rise. Molten rock (magma) from the mantle emerges through crust and boils over - sometimes violently.

12

Which plate is denser?

Oceanic plate

13

What is subduction?

When tectonic plates collide a dense oceanic plate is forced under a less dense continental plate.

14

Which igneous rock is formed from volcanoes with runny lava and a fairly safe eruption?

Iron-rich basalt

15

Which igneous rock is formed from volcanoes with thick lava and an explosive eruption?

Silica-rich Rhyolite

16

Why is it tricky to predict a volcanic eruption?

Volcanoes are unpredictable - scientists may only be able to say an eruption is more likely, not certain.

17

How are sedimentary rocks formed?

Layers of sediment laid down in lakes or seas which get buried over millions of years, squeezing out the water. Fluid flowing through pores deposit natural mineral cement.

18

What is the word equation for thermal decomposition of limestone?

calcium carbonate → calcium oxide + carbon dioxide

19

What is the symbol equation for thermal decomposition of limestone?

CaCO₃ → CaO + CO₂

20

How are metamorphic rocks formed?

Heat and pressure on sedimentary or igneous rocks over a long time. As long as they don't melt they are metamorphic.

21

What is an example of a metamorphic rock?

Marble - formed from limestone. The heat and pressure breaks down limestone so it reforms as small crystals making marble harder and it has more texture.

22

Why are ignous rocks very hard?

They contain different minerals in randomly arranged interlocking crystals.

23

What is an example of an igneous rock?

Granite - ideal for steps and buildings

24

How are aluminium and iron made?

They are extracted from their ores.

25

What is glass made from?

Heat up limestone (calcium carbonate), sand (silicon dioxide) and soda (sodium carbonate) until it melts.

26

What are bricks made from?

Clay. It is initially soft when dug up but is hardened by very high temperatures.

27

How can cement be made?

Powdered clay containing aluminium and silicates, and powdered limestone are roasted to make a complex mixture of calium and aluminium silicates.

28

How is concrete made?

Cement is mixed with sand, aggregate (gavel) and water.

29

What is reinforced concrete made of?

Concrete and solid steel supports - e.g. Steel rods. Because of this it is a composite material.

30

Why is reinforced concrete a better construction material?

It combines the hardness of concrete with the flexibility and strength of steel.

31

What are the environmental impacts of extracting rocks?

Quarrying uses land/destroys habitats and costs money to return it to new. Transporting rocks causes noise and pollution. Process produces dusta nd noise. Old sites are dangerous - disused mines are known to collapse (causing subsidence)

32

What does electrolysis mean?

Splitting up with electricity

33

What charge does the anode have?

Positive

34

What charge does the cathode have?

Negative

35

What is the reaction at the cathode for electrolysis of copper?

Cu²⁺ + 2e⁻ → Cu

36

What is the reaction at the anode for electrolysis of copper?

Cu → Cu²⁺ + 2e⁻

37

What type of reaction takes place at the cathode?

REDUCTION - electrons are gained

38

What type of reaction takes place at the anode?

OXIDATION - electrons are lost

39

Why is recycling copper better than extracting new?

Cheaper than mining and extracting from ores. Recycling uses 15% of the energy that extracting new requires.

40

What are the issues with recycling copper?

It is difficult to convince people that the effort is worth it and for them to sort their rubbish. Sorting out the copper from other metals takes time and energy.

41

What is an alloy?

A mixture of a metal other elements. They can can be two or more different metals or they can be mixture of a metal and non metal.

42

What is steel?

An alloy of iron and carbon. It is harder and stronger than iron. Steel is less likely to rust whereas iron would.

43

What is bronze an alloy of and what are its uses?

Copper and zinc. Brass is harder than either material alone and can be used in musical instruments and fixtures and fittings like screws.

44

What is solder an alloy of and what are its uses?

Lead and tin - because it solidifies as it cools it is used to solder things together.

45

What is amalgam an alloy of and what are its uses?

Mercury - a large scale use is in dentistry.

46

What is nitinol?

The name given to a family of alloys of nickel and titanium that have shape memory.

47

What alloy can be used to make spectacles?

Nitinol as the frames can be bent or sat on but still return to their normal shape.

48

What is the word equation for the rusting of iron?

iron + oxygen + water → hydrated iron (III) oxide

49

What factors increase the reaction in the rusting of iron?

If the water is acidic or salty.

50

Why doesn't aluminium corrode?

It reacts very quickly with oxygen in the air to form aluminium oxide which becomes a protective layer stopping any more reaction taking place.

51

What are the advantages of aluminium over steel?

It has a lower density, making the car lighter and giving a better fuel economy. Also it corrodes less so will have a longer lifetime.

52

What is the disadvantage of using aluminium to make car bodies?

It is much more expensive than iron or steel.

53

What part of a car is steel good for?

Bodywork because it is strong and can be hammered into sheets and welded together.

54

What part of a car is aluminium good for?

Parts of the engine - it is strong and low density so using it reduces the overall weight.

55

What part of a car is glass good for?

Its transparency is used in the windscreens and windows.

56

What part of a car is plastic good for?

It is light and hard wearing, making it useful for internal coverings on doors and dashboards. Also as electrical insulators on wires.

57

What part of a car are fibres good for?

Natural and synthetic are hard wearing and are used to cover the seats and floor.

58

What is the European Law for recycling cars?

85% of the materials in a car must be recyclable - rising to 95% by 2015

59

What is the biggest problem with recycling cars?

All the non-metal parts must be separated before they are recycled.

60

Describe universal indicator...

A combination of dyes that changes colour gradually as the pH changes.

61

What is phenolphthalein an example of?

A sudden change indicator - it goes from colourless to pink when the pH rises above 8.

62

What is an acid?

A substance with a pH less than 7. Acids form H⁺ ions in water.

63

What is pH a measure of?

The concentration of H⁺ ions

64

What is a base?

A substance with a pH over 7 and is soluble in water. They form OH⁻ ions in water.

65

What is the word equation for neutralisation?

acid + base → salt + water

66

What is the ionic equation for neutralisation?

H⁺ + OH⁻ ⇌ H₂O

67

What are the word equations for metal oxides/hydroxides?

acid + metal oxide/hydroxide → salt + water

68

Complete: acid + carbonate…

→ salt + water + carbon dioxide

69

What is the word equation for acids and ammonia?

Acid + ammonia → ammonium salt

70

What are the 3 essential elements in fertilisers and what are they needed for?

Nitrogen - making proteins (amino acids) Phosphorous - respiration and growth Potassium - helps enzymes needed for photosynthesis and respiration.

71

What must a fertiliser be able to do in order to be taken up by roots?

dissolve in water

72

Give 4 examples of fertilisers…

Ammonium nitrate, ammonium sulfate, ammonium phosphate, potassium nitrate.

73

What is the issue with fertilisers?

Eutrophication

74

What is eutrophication?

Fertilisers run off into rivers and streams, increasing levels of nitrates and phosphates. Algae uses these nutrients to multiply rapidly - algael bloom, blocking off sunlight to plants meaning they die. Aerobic bacteria which eats dead plants multiply and use all oxygen, killing fish and insects.

75

What does methyl orange indicator do?

Turns from yellow to red when alkali is neutralised (used in making ammonium nitrate)

76

How is ammonium nitrate made?

Titration - methyl orange used. Nitric acid added to ammonia - goes from yellow to red. Evaporate solution until a little solution left - leave to crystallise. To get pure, note amount of acid needed and repeat but without indicator.

77

What is the equation for the Haber process?

N₂ + 3H₂ ⇌ 2NH₃

78

Where do the reactants for the Haber process come from?

Nitrogen - from the air (makes up 78% of air) Hydrogen - from cracking of oil fractions or natural gas

79

What are the industrial conditions for making ammonia?

Pressure - High (200 atmospheres) Temperature - 450°C Catalyst - Iron

80

Why is the pressure high in the Haber Process?

It favours the forward reaction and this high pressure increases the % yield of ammonia.

81

Why is a high temperature used in the Haber process?

It favours the reverse reaction - so a high temperature decreases the % yield. 450 is optimum because it gives a fast reaction rate and a reasonable % yield (compromise).

82

What happens to unused hydrogen and nitrogen when making ammonia?

It is recycled - so nothing is wasted.

83

Why is an iron catalyst used in the Haber Process?

It makes the reaction go faster which gets it to its equilibrium proportions more quickly - but doesn’t affect the position of equilibrium or % yield.

84

What are optimum conditions?

Those that give the lowest production costs.

85

What 5 factors affect production cost?

Price of energy, cost of raw materials, labour costs/wages, plant costs (equipment), rate of production

86

What is solution mining?

Pumping hot water underground which dissolves the salt and the salt solution is forced to the surface because of the water pressure.

87

What is the issue with salt mining?

The holes must be filled in otherwise it will cause subsidence where the land collapses and slides in to the hole.

88

What is produced in the electrolysis of brine?

Hydrogen gas, chlorine gas and sodium hydroxide.

89

What is produced at the anode during the electrolysis of brine? (including half-equations)

Chlorine gas: 2Cl⁻ - 2e⁻ → Cl₂ OXIDATION

90

What is produced at the cathode during the electrolysis of brine? (including half-equations)

Hydrogen gas: 2H⁺ + 2e⁻ → H₂ REDUCTION

91

The Earth's outer layer of solid rock. Average depth of 20km

What is the crust?

92

It includes the crust and upper part of the mantle. It is made up of a jigsaw of tectonic plates and is cold and rigid - over 100km thick in places.

What is the lithosphere?

93

Solid section between the crust and core. Very rigid and temperature increases. Becomes less rigid and flows very slowly - semi liquid.

What is the mantle?

94

It is just over half the Earth's radius. 2 parts - inner core (solid) and outer core (liquid).

What is the core?

95

Radioactive decay creates lots of heat which creates convection currents in the mantle, causing the plates of the lithosphere to move.

What causes tectonic plates to move?

96

Big rocky rafts that float on the mantle because they are less dense. Move very slowly - about 2.5cm per year.

What are tectonic plates?

97

Earthquakes and volcanoes where the plates meet, caused by movement of the plates against each other.

What can tectonic plates cause?

98

The crust is too thick to drill through.

Why is it difficult to study the Earth's inner structure?

99

Using seismic waves produced by earthquakes or man made explosions. Measure the time it takes for them to travel through the Earth and where they are detected.

How can scientists study the Earth's structure?

100

P-Waves which can only travel through solids and liquids. S-Waves can only travel through solids.

What are the two types of seismic wave?

101

As an oceanic plate is forced down, it melts and starts to rise. Molten rock (magma) from the mantle emerges through crust and boils over - sometimes violently.

How are volcanoes formed?

102

Oceanic plate

Which plate is denser?

103

When tectonic plates collide a dense oceanic plate is forced under a less dense continental plate.

What is subduction?

104

Iron-rich basalt

Which igneous rock is formed from volcanoes with runny lava and a fairly safe eruption?

105

Silica-rich Rhyolite

Which igneous rock is formed from volcanoes with thick lava and an explosive eruption?

106

Volcanoes are unpredictable - scientists may only be able to say an eruption is more likely, not certain.

Why is it tricky to predict a volcanic eruption?

107

Layers of sediment laid down in lakes or seas which get buried over millions of years, squeezing out the water. Fluid flowing through pores deposit natural mineral cement.

How are sedimentary rocks formed?

108

calcium carbonate → calcium oxide + carbon dioxide

What is the word equation for thermal decomposition of limestone?

109

CaCO₃ → CaO + CO₂

What is the symbol equation for thermal decomposition of limestone?

110

Heat and pressure on sedimentary or igneous rocks over a long time. As long as they don't melt they are metamorphic.

How are metamorphic rocks formed?

111

Marble - formed from limestone. The heat and pressure breaks down limestone so it reforms as small crystals making marble harder and it has more texture.

What is an example of a metamorphic rock?

112

They contain different minerals in randomly arranged interlocking crystals.

Why are ignous rocks very hard?

113

Granite - ideal for steps and buildings

What is an example of an igneous rock?

114

They are extracted from their ores.

How are aluminium and iron made?

115

Heat up limestone (calcium carbonate), sand (silicon dioxide) and soda (sodium carbonate) until it melts.

What is glass made from?

116

Clay. It is initially soft when dug up but is hardened by very high temperatures.

What are bricks made from?

117

Powdered clay containing aluminium and silicates, and powdered limestone are roasted to make a complex mixture of calium and aluminium silicates.

How can cement be made?

118

Cement is mixed with sand, aggregate (gavel) and water.

How is concrete made?

119

Concrete and solid steel supports - e.g. Steel rods. Because of this it is a composite material.

What is reinforced concrete made of?

120

It combines the hardness of concrete with the flexibility and strength of steel.

Why is reinforced concrete a better construction material?

121

Quarrying uses land/destroys habitats and costs money to return it to new. Transporting rocks causes noise and pollution. Process produces dusta nd noise. Old sites are dangerous - disused mines are known to collapse (causing subsidence)

What are the environmental impacts of extracting rocks?

122

Splitting up with electricity

What does electrolysis mean?

123

Positive

What charge does the anode have?

124

Negative

What charge does the cathode have?

125

Cu²⁺ + 2e⁻ → Cu

What is the reaction at the cathode for electrolysis of copper?

126

Cu → Cu²⁺ + 2e⁻

What is the reaction at the anode for electrolysis of copper?

127

REDUCTION - electrons are gained

What type of reaction takes place at the cathode?

128

OXIDATION - electrons are lost

What type of reaction takes place at the anode?

129

Cheaper than mining and extracting from ores. Recycling uses 15% of the energy that extracting new requires.

Why is recycling copper better than extracting new?

130

It is difficult to convince people that the effort is worth it and for them to sort their rubbish. Sorting out the copper from other metals takes time and energy.

What are the issues with recycling copper?

131

A mixture of a metal other elements. They can can be two or more different metals or they can be mixture of a metal and non metal.

What is an alloy?

132

An alloy of iron and carbon. It is harder and stronger than iron. Steel is less likely to rust whereas iron would.

What is steel?

133

Copper and zinc. Brass is harder than either material alone and can be used in musical instruments and fixtures and fittings like screws.

What is bronze an alloy of and what are its uses?

134

Lead and tin - because it solidifies as it cools it is used to solder things together.

What is solder an alloy of and what are its uses?

135

Mercury - a large scale use is in dentistry.

What is amalgam an alloy of and what are its uses?

136

The name given to a family of alloys of nickel and titanium that have shape memory.

What is nitinol?

137

Nitinol as the frames can be bent or sat on but still return to their normal shape.

What alloy can be used to make spectacles?

138

iron + oxygen + water → hydrated iron (III) oxide

What is the word equation for the rusting of iron?

139

If the water is acidic or salty.

What factors increase the reaction in the rusting of iron?

140

It reacts very quickly with oxygen in the air to form aluminium oxide which becomes a protective layer stopping any more reaction taking place.

Why doesn't aluminium corrode?

141

It has a lower density, making the car lighter and giving a better fuel economy. Also it corrodes less so will have a longer lifetime.

What are the advantages of aluminium over steel?

142

It is much more expensive than iron or steel.

What is the disadvantage of using aluminium to make car bodies?

143

Bodywork because it is strong and can be hammered into sheets and welded together.

What part of a car is steel good for?

144

Parts of the engine - it is strong and low density so using it reduces the overall weight.

What part of a car is aluminium good for?

145

Its transparency is used in the windscreens and windows.

What part of a car is glass good for?

146

It is light and hard wearing, making it useful for internal coverings on doors and dashboards. Also as electrical insulators on wires.

What part of a car is plastic good for?

147

Natural and synthetic are hard wearing and are used to cover the seats and floor.

What part of a car are fibres good for?

148

85% of the materials in a car must be recyclable - rising to 95% by 2015

What is the European Law for recycling cars?

149

All the non-metal parts must be separated before they are recycled.

What is the biggest problem with recycling cars?

150

A combination of dyes that changes colour gradually as the pH changes.

Describe universal indicator...

151

A sudden change indicator - it goes from colourless to pink when the pH rises above 8.

What is phenolphthalein an example of?

152

A substance with a pH less than 7. Acids form H⁺ ions in water.

What is an acid?

153

The concentration of H⁺ ions

What is pH a measure of?

154

A substance with a pH over 7 and is soluble in water. They form OH⁻ ions in water.

What is a base?

155

acid + base → salt + water

What is the word equation for neutralisation?

156

H⁺ + OH⁻ ⇌ H₂O

What is the ionic equation for neutralisation?

157

acid + metal oxide/hydroxide → salt + water

What are the word equations for metal oxides/hydroxides?

158

→ salt + water + carbon dioxide

Complete: acid + carbonate…

159

Acid + ammonia → ammonium salt

What is the word equation for acids and ammonia?

160

Nitrogen - making proteins (amino acids) Phosphorous - respiration and growth Potassium - helps enzymes needed for photosynthesis and respiration.

What are the 3 essential elements in fertilisers and what are they needed for?

161

dissolve in water

What must a fertiliser be able to do in order to be taken up by roots?

162

Ammonium nitrate, ammonium sulfate, ammonium phosphate, potassium nitrate.

Give 4 examples of fertilisers…

163

Eutrophication

What is the issue with fertilisers?

164

Fertilisers run off into rivers and streams, increasing levels of nitrates and phosphates. Algae uses these nutrients to multiply rapidly - algael bloom, blocking off sunlight to plants meaning they die. Aerobic bacteria which eats dead plants multiply and use all oxygen, killing fish and insects.

What is eutrophication?

165

Turns from yellow to red when alkali is neutralised (used in making ammonium nitrate)

What does methyl orange indicator do?

166

Titration - methyl orange used. Nitric acid added to ammonia - goes from yellow to red. Evaporate solution until a little solution left - leave to crystallise. To get pure, note amount of acid needed and repeat but without indicator.

How is ammonium nitrate made?

167

N₂ + 3H₂ ⇌ 2NH₃

What is the equation for the Haber process?

168

Nitrogen - from the air (makes up 78% of air) Hydrogen - from cracking of oil fractions or natural gas

Where do the reactants for the Haber process come from?

169

Pressure - High (200 atmospheres) Temperature - 450°C Catalyst - Iron

What are the industrial conditions for making ammonia?

170

It favours the forward reaction and this high pressure increases the % yield of ammonia.

Why is the pressure high in the Haber Process?

171

It favours the reverse reaction - so a high temperature decreases the % yield. 450 is optimum because it gives a fast reaction rate and a reasonable % yield (compromise).

Why is a high temperature used in the Haber process?

172

It is recycled - so nothing is wasted.

What happens to unused hydrogen and nitrogen when making ammonia?

173

It makes the reaction go faster which gets it to its equilibrium proportions more quickly - but doesn’t affect the position of equilibrium or % yield.

Why is an iron catalyst used in the Haber Process?

174

Those that give the lowest production costs.

What are optimum conditions?

175

Price of energy, cost of raw materials, labour costs/wages, plant costs (equipment), rate of production

What 5 factors affect production cost?

176

Pumping hot water underground which dissolves the salt and the salt solution is forced to the surface because of the water pressure.

What is solution mining?

177

The holes must be filled in otherwise it will cause subsidence where the land collapses and slides in to the hole.

What is the issue with salt mining?

178

Hydrogen gas, chlorine gas and sodium hydroxide.

What is produced in the electrolysis of brine?

179

Chlorine gas: 2Cl⁻ - 2e⁻ → Cl₂ OXIDATION

What is produced at the anode during the electrolysis of brine? (including half-equations)

180

Hydrogen gas: 2H⁺ + 2e⁻ → H₂ REDUCTION

What is produced at the cathode during the electrolysis of brine? (including half-equations)