C6 - Chemistry Out There Flashcards

Question 1

Q

C6 - Chemistry Out There

What is reduction?

Answer

A

Gain of electrons

Question 2

Q

C6 - Chemistry Out There

What does an oxidising agent do?

Answer

A

Accept electrons and gets reduced

Question 3

Q

C6 - Chemistry Out There

What does a reducing agent do?

Answer

A

Donate electrons and get oxidised

Question 4

Q

C6 - Chemistry Out There

What does displacement reactions involve?

Answer

A

One metal kicking another one out of a compound

Question 5

Q

C6 - Chemistry Out There

What is the rule for displacement reactions?

Answer

A

A more reactive metal will displace a less reactive metal from its compound

Question 6

Q

C6 - Chemistry Out There

Why do some iron and steels rust?

Answer

A

When they come into contact with air and water

Question 7

Q

C6 - Chemistry Out There

When does rusting of iron only occur?

Answer

A

When iron is in contact with both water and oxygen

Question 8

Q

C6 - Chemistry Out There

What is rust a form of?

Answer

A

Hydrated iron (III) oxide

Question 9

Q

C6 - Chemistry Out There

What is the equation for rusting?

Answer

A

Iron + oxygen + water -> hydrated iron (III) oxide

Question 10

Q

C6 - Chemistry Out There

What type of reaction is rusting of iron?

Question 11

Q

C6 - Chemistry Out There

What happens to iron when it reacts with oxygen?

Answer

A

Loses electrons - oxidised. Each Fe atom loses 3 electrons to become Fe³⁺.

Question 12

Q

C6 - Chemistry Out There

What happens to oxygen when it reacts with iron?

Answer

A

Reduced. Each O atom gains 2 electrons to become O^2-.

Question 13

Q

C6 - Chemistry Out There

What are the 4 ways to prevent rusting?

Answer

A

Make alloys. Barrier. Tin coating/plating. More reactive metals (galvanising)

Question 14

Q

C6 - Chemistry Out There

What are steels alloys of?

Answer

A

Iron with carbon and small quantities of other metals

Question 15

Q

C6 - Chemistry Out There

What is stainless steel?

Answer

A

One of most common steels - rustproof alloy of iron, carbon and chromium.

Question 16

Q

C6 - Chemistry Out There

How does a barrier prevent rusting?

Answer

A

Keeps out water, oxygen or both.

Question 17

Q

C6 - Chemistry Out There

How is painting ideal to prevent rusting?

Answer

A

Ideal for large and small structures. Nice and colourful.

Question 18

Q

C6 - Chemistry Out There

How is oiling or greasing used to prevent rusting?

Answer

A

Has to be used when moving parts are involved e.g. Bike chains

Question 19

Q

C6 - Chemistry Out There

What is tin plating?

Answer

A

A coat of tin is applied to the object e.g. Food cans.

Question 20

Q

C6 - Chemistry Out There

How does tin plating prevent rusting?

Answer

A

Acts as a barrier, stopping water and oxygen from reaching iron surface.

Question 21

Q

C6 - Chemistry Out There

Tin plating only as long as…

Answer

A

Tin remains intact. If scratched, iron will lose electrons and rust even faster.

Question 22

Q

C6 - Chemistry Out There

Why is it not always a good idea to buy reduced bashed tins?

Answer

A

They could be starting to rust.

Question 23

Q

C6 - Chemistry Out There

How does the sacrificial method work?

Answer

A

Place a more reactive metal with the iron. Water and oxygen react with the sacrificial metal instead of iron.

Question 24

Q

C6 - Chemistry Out There

What is galvanising?

Answer

A

A coat of zinc put on object. Zinc is sacrificial protection - more reactive - loses electrons in preference to iron.

Question 25

Q

C6 - Chemistry Out There

What sort of items are galvanised?

Answer

A

Steel buckets and corrugated iron roofing

Question 26

Q

C6 - Chemistry Out There

How can blocks of metal prevent rusting?

Answer

A

E.g. Magnesium can be bolted onto iron. Magnesium loses electrons in preference to iron.

Question 27

Q

C6 - Chemistry Out There

When are block of metal used on items?

Answer

A

Hulls of ships and underground iron pipes.

Question 28

Q

C6 - Chemistry Out There

What is oxidation?

Answer

A

Loss of electrons

Question 29

Q

C6 - Chemistry Out There

What does electrolysis mean?

Answer

A

Breaking down a substance with electricity

Question 30

Q

C6 - Chemistry Out There

How does electrolysis work?

Answer

A

Electric current passed through a molten or dissolved ionic compound, causing it to decompose. This creates a flow of charge through the electrolyte.

Question 31

Q

C6 - Chemistry Out There

What happens to the positive ions in electrolysis?

Answer

A

Move towards the cathode (-ve) and gain electrons.

Question 32

Q

C6 - Chemistry Out There

What happens to negative ions in electrolysis?

Answer

A

Move towards anode (+ve) and lose electrons

Question 33

Q

C6 - Chemistry Out There

What happens in electrolysis when ions lose or gain electrons?

Answer

A

They become atoms or molecules and are discharged from the solution at the electrodes.

Question 34

Q

C6 - Chemistry Out There

What is the ionic equation at the anode during electrolysis of copper (II) sulfate?

Answer

A

4OH^- - 4e^- → O₂ + 2H₂O

Question 35

Q

C6 - Chemistry Out There

What is the ionic equation at the cathode during electrolysis of copper (II) sulfate?

Answer

A

Cu²⁺ + 2e^-→ Cu

Question 36

Q

C6 - Chemistry Out There

What are ions are there in aqueous solutions?

Answer

A

Hydrogen ions (H⁺), hydroxide ions (OH^-) and ions from the solute (ionic compounds)

Question 37

Q

C6 - Chemistry Out There

What is it sometimes easier to do in electrolysis?

Answer

A

Discharge ions from the water instead of from the solute

Question 38

Q

C6 - Chemistry Out There

What does discharging ions from the water instead of the solute do in electrolysis?

Answer

A

Produce hydrogen at the cathode and oxygen at the anode.

Question 39

Q

C6 - Chemistry Out There

What ions does a solution of aqueous sulfuric acid contain?

Answer

A

SO₄^2-, H⁺, OH^-

Question 40

Q

C6 - Chemistry Out There

What is the equation at the cathode for electrolysis with sulfuric acid?

Answer

A

2H⁺ + 2e^- → H₂

Question 41

Q

C6 - Chemistry Out There

What is the equation at the anode for electrolysis with sulfuric acid?

Answer

A

4OH^-- 4e^- → O₂ + 2H₂O

Question 42

Q

C6 - Chemistry Out There

What reaction takes place at the anode?

Answer

A

Oxidation

Question 43

Q

C6 - Chemistry Out There

What reaction takes place at the cathode?

Answer

A

Reduction

Question 44

Q

C6 - Chemistry Out There

Where is hydrogen produced in electrolysis?

Question 45

Q

C6 - Chemistry Out There

Where is oxygen produced in electrolysis?

Question 46

Q

C6 - Chemistry Out There

What is the reaction at the cathode for the electrolysis of copper(II) sulfate solution?

Answer

A

Cu²⁺ + 2e^- → Cu

Question 47

Q

C6 - Chemistry Out There

What is the reaction at the anode for the electrolysis of copper(II) sulfate solution?

Answer

A

4OH^- - 4e^- -> O₂ + 2H₂O

Question 48

Q

C6 - Chemistry Out There

What charge does the cathode have?

Question 49

Q

C6 - Chemistry Out There

What charge does the anode have?

Question 50

Q

C6 - Chemistry Out There

What happens when chlorine gas is passed through a solution of iron(II) salt?

Answer

A

Solution turns from green to yellow

Question 51

Q

C6 - Chemistry Out There

Why does the solution change colour when chlorine gas is passed through a solution of iron(II) salt?

Answer

A

Iron (II) ion is oxidised to iron (III). Fe²⁺ ion loses an electron to form Fe³⁺

Question 52

Q

C6 - Chemistry Out There

What causes the reaction to oxidise and turn a different colour when chlorine gas is passed through a solution of iron(II) salt?

Answer

A

Oxidising agent - chlorine gas

Question 53

Q

C6 - Chemistry Out There

What must be the reducing agent when chlorine gas is passed through a solution of iron(II) salt?

Answer

A

Iron (II) ion

Question 54

Q

C6 - Chemistry Out There

What happens to the chlorine when chlorine gas is passed through a solution of iron(II) salt?

Answer

A

Chlorine gains the electron Fe²⁺ lost. Chlorine reduced.

Question 55

Q

C6 - Chemistry Out There

When iron atoms are reacted with dilute acid how are iron (II) ions formed?

Answer

A

When iron atoms are oxidised.

Question 56

Q

C6 - Chemistry Out There

When iron atoms are reacted with dilute acid what happens to the iron atoms?

Answer

A

Lose electrons - oxidised by hydrogen ions

Question 57

Q

C6 - Chemistry Out There

When iron atoms are reacted with dilute acid what happens to the hydrogen atoms?

Answer

A

Gain electrons - reduced by iron atoms.

Question 58

Q

C6 - Chemistry Out There

What is the order of reactivity for zinc, iron, magnesium and tin/copper from most reactive to least reactive?

Answer

A

Magnesium, zinc, iron, tin/copper.

Question 59

Q

C6 - Chemistry Out There

What happens to metal ions in displacement reactions?

Answer

A

Gain electrons - are reduced

Question 60

Q

C6 - Chemistry Out There

What happens to the metal atoms in displacement reactions?

Answer

A

Loses electrons - are oxidised

Question 61

Q

C6 - Chemistry Out There

What happens between hard water and soap?

Answer

A

Doesn’t lather. Makes scum

Question 62

Q

C6 - Chemistry Out There

What do you need to do to get a good lather with hard water?

Answer

A

Add more soap, use softer water.

Question 63

Q

C6 - Chemistry Out There

What does hard water form on pipes/kettles/boilers?

Answer

A

Limescale (calcium carbonate)

Question 64

Q

C6 - Chemistry Out There

What does limescale act as?

Answer

A

Thermal insulator

Answer 60

A

Kettle with limescale in heating element will take longer to boil.

Answer 61

A

Block them

Answer 62

A

Calcium ions (Ca²⁺), magnesium ions (Mg²⁺), or both.

Answer 63

A

The soils/rocks contain Ca and Mg compounds - these ions dissolve in the water.

Answer 64

A

Chalk, limestone and marble.

Answer 65

A

No but reacts with acids.

Answer 66

A

Carbon dioxide from air dissolves in rainwater forming carbonic acid.

Answer 67

A

Carbon dioxide + water → carbonic acid

Answer 68

A

CO₂ + H₂O -> H₂CO₃

Answer 69

A

H₂CO₃

Answer 70

A

Calcium carbonate

Answer 71

A

Carbon dioxide + water + calcium carbonate → calcium hydrogencarbonate

Answer 72

A

H₂CO₃ + CaCO₃ → Ca(HCO₃)₂

Answer 73

A

Temporary and permanent

Answer 74

A

Hydrogencarbonate ion (HCO₃^-) in Ca(HCO₃)₂

Answer 75

A

Dissolved calcium sulfate (amongst other things)

Answer 76

A

By boiling

Answer 77

A

Calcium hydrogencarbonate decomposes to form insoluble calcium carbonate.

Answer 78

A

Calcium carbonate precipitate (limescale) is insoluble

Answer 79

A

Calcium hydrogencarbonate → calcium carbonate + water + carbon dioxide

Answer 80

A

Ca(HCO₃)₂ _(aq) → CaCO₃ _(s) + H₂O _(l) + CO_{2 (g)}

Answer 81

A

Using washing soda (sodium carbonate, NaCO₃) or by ‘ion exchange resin’.

Answer 82

A

Carbonate ions join to calcium ions to make insoluble precipitate of calcium carbonate. Works whether hardness is due to calcium sulfate or calcium hydrogencarbonate.

Answer 83

A

Ca²⁺ _(aq) + CO₃^2-_(aq) → CaCO_{3 (s)}

Answer 84

A

Lots of sodium ions (or hydrogen ions) and these are exchanged for calcium or magnesium ions.

Answer 85

A

100cm³ of water - conical flask
Add 1cm³ of soap solution. Bung in and shake.
Repeat until lasting lather formed (bubbles cover surface for at least 30 secs)
Record amount of soap needed.

Answer 86

A

What is reduction?

Answer 87

A

What does an oxidising agent do?

Answer 88

A

What does a reducing agent do?

Answer 89

A

What does displacement reactions involve?

Answer 90

A

What is the rule for displacement reactions?

Answer 91

A

Why do some iron and steels rust?

Answer 92

A

When does rusting of iron only occur?

Answer 93

A

What is rust a form of?

Answer 94

A

What is the equation for rusting?

Answer 95

A

What type of reaction is rusting of iron?

Answer 96

A

What happens to iron when it reacts with oxygen?

Answer 97

A

What happens to oxygen when it reacts with iron?

Answer 98

A

What are the 4 ways to prevent rusting?

Answer 99

A

What are steels alloys of?

Answer 100

A

What is stainless steel?

Answer 101

A

How does a barrier prevent rusting?

Answer 102

A

How is painting ideal to prevent rusting?

Answer 103

A

How is oiling or greasing used to prevent rusting?

Answer 104

A

What is tin plating?

Answer 105

A

How does tin plating prevent rusting?

Answer 106

A

Tin plating only as long as…

Answer 107

A

Why is it not always a good idea to buy reduced bashed tins?

Answer 108

A

How does the sacrificial method work?

Answer 109

A

What is galvanising?

Answer 110

A

What sort of items are galvanised?

Answer 111

A

How can blocks of metal prevent rusting?

Answer 112

A

When are block of metal used on items?

Answer 113

A

What is oxidation?

Answer 114

A

What does electrolysis mean?

Answer 115

A

How does electrolysis work?

Answer 116

A

What happens to the positive ions in electrolysis?

Answer 117

A

What happens to negative ions in electrolysis?

Answer 118

A

What happens in electrolysis when ions lose or gain electrons?

Answer 119

A

What is the ionic equation at the anode during electrolysis of copper (II) sulfate?

Answer 120

A

What is the ionic equation at the cathode during electrolysis of copper (II) sulfate?

Answer 121

A

What are ions are there in aqueous solutions?

Answer 122

A

What is it sometimes easier to do in electrolysis?

Answer 123

A

What does discharging ions from the water instead of the solute do in electrolysis?

Answer 124

A

What ions does a solution of aqueous sulfuric acid contain?

Answer 125

A

What is the equation at the cathode for electrolysis with sulfuric acid?

Answer 126

A

What is the equation at the anode for electrolysis with sulfuric acid?

Answer 127

A

What reaction takes place at the anode?

Answer 128

A

What reaction takes place at the cathode?

Answer 129

A

Where is hydrogen produced in electrolysis?

Answer 130

A

Where is oxygen produced in electrolysis?

Answer 131

A

What is the reaction at the cathode for the electrolysis of copper(II) sulfate solution?

Answer 132

A

What is the reaction at the anode for the electrolysis of copper(II) sulfate solution?

Answer 133

A

What charge does the cathode have?

Answer 134

A

What charge does the anode have?

Answer 135

A

What happens when chlorine gas is passed through a solution of iron(II) salt?

Answer 136

A

Why does the solution change colour when chlorine gas is passed through a solution of iron(II) salt?

Answer 137

A

What causes the reaction to oxidise and turn a different colour when chlorine gas is passed through a solution of iron(II) salt?

Answer 138

A

What must be the reducing agent when chlorine gas is passed through a solution of iron(II) salt?

Answer 139

A

What happens to the chlorine when chlorine gas is passed through a solution of iron(II) salt?

Answer 140

A

When iron atoms are reacted with dilute acid how are iron (II) ions formed?

Answer 141

A

When iron atoms are reacted with dilute acid what happens to the iron atoms?

Answer 142

A

When iron atoms are reacted with dilute acid what happens to the hydrogen atoms?

Answer 143

A

What is the order of reactivity for zinc, iron, magnesium and tin/copper from most reactive to least reactive?

Answer 144

A

What happens to metal ions in displacement reactions?

Answer 145

A

What happens to the metal atoms in displacement reactions?

Answer 146

A

What happens between hard water and soap?

Answer 147

A

What do you need to do to get a good lather with hard water?

Answer 148

A

What does hard water form on pipes/kettles/boilers?

Answer 149

A

What does limescale act as?

Answer 150

A

How is a kettle with limescale different to a clean kettle?

Answer 151

A

What can limescale eventually do to pipes?

Answer 152

A

What does hard water contain?

Answer 153

A

What happens as water flows over rocks and through soil?

Answer 154

A

What does magnesium sulfate dissolve in?

Answer 155

A

What does calcium carbonate commonly exist as?

Answer 156

A

Does calcium carbonate dissolve in water?

Answer 157

A

How do we know rainwater is slightly acidic?

Answer 158

A

What is the word equation when rainwater reacts with carbon dioxide?

Answer 159

A

What is the symbol equation when rainwater reacts with carbon dioxide?

Answer 160

A

What is the molecular formula of carbonic acid?

Answer 161

A

What can rainwater react with to form calcium hydrogencarbonate?

Answer 162

A

What is the word equation for producing calcium hydrogencarbonate?

Answer 163

A

What is the symbol equation for producing calcium hydrogencarbonate?

Answer 164

A

What are the two types of hardness?

Answer 165

A

What is temporary hardness caused by?

Answer 166

A

What is permanent hardness caused by?

Answer 167

A

How is temporary hardness removed?

Answer 168

A

What does boiling do to temporary hardness?

Answer 169

A

Why doesn’t boiling remove permanent hardness?

Answer 170

A

What is the word equation for removing temporary hardness?

Answer 171

A

What is the symbol equation for removing temporary hardness?

Answer 172

A

How can bot types of hardness be removed?

Answer 173

A

How does NaCO₃ remove both types of hardness?

Answer 174

A

What is the ionic equation for removing hardness with sodium carbonate?

Answer 175

A

How does ‘ion exchange resin work’?

Answer 176

A

What is the method for comparing the hardness of water samples?

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C6 - Chemistry Out There Flashcards

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