Extraction And Uses Of Metals

Question 1

The extraction of metals depends on…

Answer 1

Its position in the reactivity series and cost

Question 2

Electrolysis is used for metals…

Answer 2

More reactive than zinc

Question 3

Heating with Carbon or carbon monoxide (as a reducing agent) is used to separate metals…

Answer 3

Up to zinc

Question 4

Aluminium is extracted from an ore called…

Answer 4

Bauxite

Question 5

Bauxite is…

Answer 5

Impure aluminium oxide

Question 6

The half equations for the extraction of aluminium are…

Answer 6

Al(3+) + 3e- = Al
(Aluminium ions are attracted to the cathode and reduced)
2O(2-) = O2 + 4e-
(Oxide ions are attracted to the anode and oxidised)

Question 7

Melting aluminium oxide requires…

Answer 7

Extremely high temperatures

Question 8

To lower the melting point, aluminium oxide is…

Answer 8

Dissolved in an aluminium compound called cryolite as a flux to lower its melting point

Question 9

Because of high temperatures in electrolysis the Carbon anodes will…

Answer 9

Burn with with the oxygen produced to form Carbon dioxide, so they have to be replaced regularly

Question 10

One problem with electrolysis is…

Answer 10

The cost. The electricity requires cells with currents up to 100 000A

Question 11

Properties that make aluminium good in aircraft:

Answer 11

It resists corrosion due to its aluminium oxide coat
It has a low density
It is strong

Question 12

Properties that make aluminium oxide good for saucepans

Answer 12

It remains shiny
It is a good conductor of heat
It resists corrosion
It has a low density

Question 13

Iron is extracted from … In a …

Answer 13

Haematite, which contains Iron (III) oxide, in a blast furnace

Question 14

Coke is…

Answer 14

Impure Carbon

Question 15

Coke burns to form…

Answer 15

Carbon dioxide

Question 16

Coke burning is a … Reaction, which …

Answer 16

Strongly exothermic reaction which heats the blast furnace

Question 17

The equation for Coke burning is…

Answer 17

C + O2 = CO2

Question 18

Carbon monoxide is the main … In a blast furnace

Answer 18

Reducing agent

Question 19

The equation for iron oxide reacting with Carbon monoxide is…

Answer 19

Fe2O3 + 3CO = 2Fe + 3CO2

Question 20

The equation for iron (III) oxide being reduced by Carbon is…

Answer 20

Fe2O3 + 3C = 2Fe + 3CO

Question 21

The heat of the furnace causes the limestone to…

Answer 21

Thermically decompose

Question 22

Limestone thermos lily decomposes to form…

Answer 22

Calcium oxide and Carbon dioxide

Question 23

The equation for limestone thermography decomposing is…

Answer 23

CaCO3 = CaO + CO2

Question 24

A blast furnace is hottest at the top/bottom

Answer 24

Bottom. 400 oC at the top, 1800 oC at the bottom

Question 25

One of the impurities found in haematite is...

Answer 25

Silicone dioxide SiO2

Question 26

Calcium oxide on the blast furnace reacts with...

Answer 26

Silicone dioxide SiO2

Question 27

When calcium oxide and silicone dioxide react they produce

Answer 27

Molten calcium silicate (slag)

Question 28

The equation for slag forming is...

Answer 28

SiO2 + CaO = CaSiO3

Question 29

Wrought iron is ...% iron and is used for...

Answer 29

100% iron and is used for decorative work such as gates and railings as it is very soft

Question 30

Mild steel is ...% ... And is used for

Answer 30

0.25% Carbon and is used for nails, car bodies and ship building as it is tough and malleable

Question 31

High Carbon Steel is ...% Carbon and is used for ... As it is...

Answer 31

0.25 - 1.5% Carbon and is used for cutting tools as it is very hard

Question 32

Cast iron is ...% ... And is used for ... As it is ...

Answer 32

About 4% Carbon and is used for manhole covers, guttering and engine blocks as it is very brittle but strong

Question 33

Stainless steel is iron mixed with ... And it is used for ... As it is...

Answer 33

Chromium and nickel and is used for cutlery and cooking utensils as it resists rusting but is expensive