Extraction and use of metals

Question 1

the more reactive a metal is…

Answer 1

the harder it is to extract it from a compound

Question 2

lots of common metals react with…to form…

Answer 2

oxygen…oxides

Question 3

what is the reaction that involves the separation of a metal from the oxygen?

Answer 3

a reduction reaction

Question 4

what is the reducing agent?

Answer 4

the substance that reduces the metal

Question 5

what is the most common reducing agent?

Answer 5

carbon

Question 6

copper oxide is reduced to copper:

Answer 6

2CuO + C = 2Cu + CO2

Question 7

Methods of extraction are linked to the…

Answer 7

order of reactivity

Question 8

only metals…than…can be reduced by…

Answer 8

less reactive…carbon…carbon

Question 9

very reactive metals form…

Answer 9

very stable ores

Question 10

metals that are more reactive than carbon need to be extracted using…

Answer 10

electrolysis

Question 11

what is the melting point of aluminium?

Answer 11

2000 degrees celcius

Question 12

what is aluminium dissolved in?

Answer 12

molten cryolite (a less common ore than aluminium)

Question 13

What does the molten cryolite do?

Answer 13

it brings the temperature down to about 900 degrees celcius

Question 14

what electrode are the aluminium ions attracted to?

Answer 14

the negative

Question 15

what happens to the aluminium atoms once they gain electrons?

Answer 15

they sink to the bottom

Question 16

why do the positive electrodes always need to be replaced?

Answer 16

they get worn down by reacting with oxygen

Question 17

at the negative electrode:

Answer 17

Al3+ + 3e- –> Al

Question 18

at the positive electrode:

Answer 18

202- –> O2 + 4e-

Question 19

why is electrolysis expensive?

Answer 19

• it uses lots of electricity
• the need to heat the electrolyte
• the frequent replacement of electrodes

Question 20

what are the raw materials used for extracting iron from iron ore?

Answer 20

• iron ore
• coke
• limestone

Question 21

what is coke?

Answer 21

almost pure carbon

Question 22

what is the purpose of limestone?

Answer 22

to take away impurities in the form of slag

Question 23

step 1:

Answer 23

hot air is blasted into the furnace, making the coke burn much faster than normal
this raises the temperature to about 1500 degrees Celsius

Question 24

Step 2:

Answer 24

the coke burns to produce carbon dioxide

Question 25

step 2 equation:

Answer 25

C + O2 --> CO2

Question 26

step 3:

Answer 26

the carbon dioxide then reacts with the unburnt coke to form carbon monoxide

Question 27

step 3 equation:

Answer 27

CO2 + C --> 2CO

Question 28

Step 4:

Answer 28

the carbon monoxide then reduces the iron ore to iron

Question 29

step 4 equation:

Answer 29

3CO + Fe2O3 --> 3CO2 + 2Fe

Question 30

step 5:

Answer 30

the iron is molten at this temperature but is also very dense, so it runs straight to the bottom of the furnace where it's tapped off

Question 31

What is the main impurity from this process?

Answer 31

sand (silicon dioxide)

Question 32

what removes the impurity?

Answer 32

the limestone

Question 33

Step 1 of removing the impurity:

Answer 33

the limestone is decomposed by the heat into calcium oxide and carbon dioxide

Question 34

Step 1 of removing the impurity: equation

Answer 34

CaCO3 --> CaO + CO2

Question 35

Step 2 of removing the impurity:

Answer 35

the calcium oxide reacts with the sand to form calcium silicate, or slag, which is molten and can be tapped off

Question 36

What is the cooled slag used for?

Answer 36

- road building | - fertiliser

Question 37

what are the properties of aluminium and iron? (6)

Answer 37

- both dense and lustrous (shiny) - high melting points - high tensile strength - malleable - good conductors of electricity - good conductors of heat energy

Question 38

uses of iron:

Answer 38

- wrought iron (malleable) | - alloys

Question 39

what is cast iron made of?

Answer 39

iron, carbon and silicon

Question 40

what is steel made of?

Answer 40

iron, carbon and usually some other metals

Question 41

what is the main problem with iron?

Answer 41

it corrodes easily

Question 42

uses of aluminium:

Answer 42

- it doesnt corrode so is used for products that come into contact with water (eg drinks cans) - aluminium is much less dense than iron so can be used for bicycle frames and aeroplanes

Question 43

What is ammonia used for?

Answer 43

Fertilisers Making nitric acid Making nylon

Question 44

Where does the nitrogen come from?

Answer 44

Air

Question 45

Where does the hydrogen come from?

Answer 45

Natural gas

Question 46

What temperature does the Haber process happen at?

Answer 46

450

Question 47

What pressure does the haber process happen at?

Answer 47

200 atm

Question 48

What is the catalyst used for the Haber process?

Answer 48

Iron

Question 49

First step contact process

Answer 49

Majing sulfur dioxide

Question 50

Second step contact process

Answer 50

Making sulfur trioxide

Question 51

Third step contact process

Answer 51

Making liquid oleum

Question 52

Fourth step contact process

Answer 52

Making concentrated sulfuric acid

Question 53

Uses for sulfuric acid

Answer 53

Fertilisers Detergents Paints

Question 54

Temperature contact process

Answer 54

450

Question 55

Pressure contact process

Answer 55

2 atm

Question 56

Catalyst contact process

Answer 56

Vanadium(v) oxide