Metals

Question 1

What are the downsides to mining for metal?

Answer 1

Pollution
Landscape scars
Habitat destruction

Question 2

What are the properties of copper?

Answer 2

Unreactive - So no reaction when combined with water which gives it a longer useful lifespan
Malleable
Conducts electricity and heat well

Question 3

What is the most reactive metal?

Answer 3

Potassium

Question 4

What is a native metal?

Answer 4

One that is found pure in its metallic form in nature e.g. gold & silver

Question 5

What will a more reactive metal displace a less reactive one from?

Answer 5

A solution of one of its salts (compound)

Question 6

Is a displacement reaction endothermic or exothermic?

Answer 6

Exothermic

Question 7

What is a competition reaction?

Answer 7

When a more reactive metal removes oxygen from the oxide of a less reactive metal

Question 8

Where are transition metals found in the periodic table?

Answer 8

The centre

Question 9

What properties do transition metals have?

Answer 9

High mpt & bpt
Malleable
High density
Good conductors of heat & electricity
Less reactive than alkali metals

Question 10

What are the colours of compounds/solutions of Fe2+, Fe3+ and Cu2+ ions?

Answer 10

Fe2+ = Pale green
Fe3+ = Brown
Cu2+ = Blue

Question 11

How can we test for the presence of transition metal ions?

Answer 11

By using a solution of sodium hydroxide

Question 12

What precipitates do Copper, Iron(II) and Iron (III) reactions with sodium hydroxide solution create?

Answer 12

Cu2+ = Blue precipitate [Cu(OH)2)(s)]
Fe2+ = Green precipitate [Fe(OH)2(s)]
Fe3+ = Orange/Brown precipitate [Fe(OH)3(s)]

Question 13

What is an alloy?

Answer 13

A combination of 2+ elements, where at least 1 is a metal. It is a mixture.

Question 14

Why is the alloy steel more useful than iron?

Answer 14

It is harder and stronger

Question 15

How can different types of steel be made?

Answer 15

By changing its composition e.g. varying carbon content (steel is made from iron and carbon)

Mild steel (little carbon) is malleable and easily shaped
High carbon steel is harder and more brittle

Question 16

What are the raw materials that go inside of a blast furnace and what functions do they serve?

Answer 16

Iron ore - Source of iron
Coke - Acts as a fuel (produces carbon monoxide for the reaction)
Limestone - Removes sandy impurities
Hot air - Provides oxygen so that coke can burn

Question 17

What happens inside a blast furnace?

Answer 17

Industrial reduction of iron oxide

Question 18

What are the 4 chemical processes that take place in the blast furnace?

Answer 18

1) Combustion
Coke burns in hot air to produce carbon monoxide
2)Reduction of iron (II) oxide
Iron oxide is reduced into iron
3) Decomposition of calcium carbonate
Limestone thermally decomposes to form calcium oxide
4) Neutralisation of silicon dioxide
Basic CaO reacts with sandy impurities to produce slag (Calcium silicate)
(CaO is a base and SiO2 is acidic so they neutralise each other)

Question 19

How do molter slag and molten iron remain separate at the bottom of the blast furnace?

Answer 19

Molten slag is less dense than the iron and so stays on top

Question 20

What does it mean when it is said that the process inside of a blast furnace is continuous? Why does it need to be this way?

Answer 20

The furnace is kept hot and new materials are constantly added. This is because getting the furnace up to the temperature required takes a lot of time and energy.

Question 21

What is electrolysis?

Answer 21

Splitting a compound using electricity

Question 22

What is electrolysis used for?

Answer 22

It is used industrially in the production of reactive metals such as aluminium from their ores

Question 23

What are the positive and negative electrodes called?

Answer 23

Pos = Anode
Neg = Cathode

Question 24

What is an electrode typically made of?

Answer 24

Metal or graphite because they can conduct electricity

Question 25

What is the name for the compound that is being split in electrolysis?

Answer 25

The electrolyte

Question 26

What occurs at the cathode during electrolysis?

Answer 26

Positive ions are attracted and they gain electrons. This is called reduction

Question 27

What occurs at the anode during electrolysis?

Answer 27

Negative ions are attracted and they lose electrons. This is called oxidisation

Question 28

Why is cryolite added to the electrolyte in electrolysis?

Answer 28

To reduce the melting temperature. This saves a lot of electrical energy and money

Question 29

Where would you geographically put a metal plant?

Answer 29

On the coast - Ore needs to be imported Near a power station - Needs a source of cheap electricity because so much is used Away from major population centres Near good transport system Not to far from civilisation - Need staff

Question 30

Why does the electrolyte in electrolysis need to be molten?

Answer 30

So that the ions can move

Question 31

What uses does aluminium have?

Answer 31

Aeroplanes - Low dendity Foil - Protective oxide layer prevents is from reacting with food Overhead power lines - Good conductor of electricity + low density prevents wires from sagging

Question 32

What uses does copper have?

Answer 32

Wires - Ductile so can be stretched into wire shape + good conductor Plumbing - Does not react with water (doesn't corrode) Cooking - Good conductor + doesn't react with water

Question 33

What uses does titanium have?

Answer 33

Artificial hip joints - Low density Fighter aircraft - Hard + strong Pipes in nuclear power stations - Thin protective layer of oxides prevents corrosion + very high mpt

Question 34

What is collected at each electrode during the electrolysis of water?

Answer 34

Hydrogen gas at the cathode and oxygen gas at the anode

Question 35

Will more hydrogen or oxygen be produced in the electrolysis of water?

Answer 35

Twice as much hydrogen is formed as oxygen as for every oxygen atom in a molecule in water there are two hydrogen atoms

Question 36

What is produced at the electrodes in the electrolysis of aqueous solutions?

Answer 36

``` Cathode - Metals lower than hydrogen in the reactivity series Anode - The metal e.g. Copper (II) chloride Cath - Cu An - Cl2 ``` When the dissolved salt includes ions from metals that are higher than hydrogen in the reactivity series, hydrogen gas is formed rather than the metal at the cathode

Question 37

What could you expect to see at each electrode after electrolysis of copper oxide?

Answer 37

Cathode - A coating of copper | Anode - Oxygen gas bubbles

Question 38

What is a disadvantage of using electrolysis to extract reactive metals?

Answer 38

Very expensive

Question 39

In the electrolysis of aqueous solutions, what products can form at the anode?

Answer 39

1) Oxygen gas 2) A halogen (fluorine, chlorine, bromine, iodine, or astatine) When no halogens are present oxygen will be produced by the OH- ions present in the solution

Question 40

In the electrolysis of aqueous solutions, what products can form at the cathode?

Answer 40

1) Hydrogen gas 2) A metal The metal will only be produced if it is lower in the reactivity series than hydrogen (e.g. copper)

Question 41

What characterises a more reactive met

Answer 41

A metal that forms a positive ion more easily

Question 42

Why is carbon used to extract metals from their oxides?

Answer 42

Good conductor + Cheap

Question 43

What is produced when reactive metals react with cold water?

Answer 43

Metal hydroxide + Hydrogen gas

Question 44

What are the 2 types of metal in the periodic table?

Answer 44

Transition metals | Alkali metals

Question 45

Why effect does its ionic structure have on an alloy?

Answer 45

The ions are of different sizes which makes it more difficult for layers to slide over each other (makes alloy stronger)