Extraction reactions of metals

Question 1

List the methods of extracting a metal from its oxide (3)

Answer 1

Displacement reaction with Carbon, Electrolysis, Displacement reaction with another more reactive metal

Question 2

What will happen in a reaction between Zinc Sulphate + copper

Answer 2

No reaction

Question 3

What will happen in a reaction between Copper Sulfate + Zinc

Answer 3

Copper Sulfate + Zinc to Zinc Sulfate + Copper

Question 4

What is the symbolic equation between Copper Sulfate and Zinc

Answer 4

CuSO4+Zn → ZnSO4+ Cu

Question 5

What is the Termite Reaction+ equation

Answer 5

It is displacement, exothermic reaction between Fe2O3+2Al → 2Fe+Al2O3

Question 6

What is being used to extract iron from its ore?

Answer 6

Blast furnace

Question 7

What chemicals are used for iron extraction?

Answer 7

Iron ore is mixed with Coke and Limestone

Question 8

Why is Limestone being used in the extraction(equation + state symbols)

Answer 8

To remove impurities from iron ore. Limestone is decomposed in heat. CaCO3(s) → CaO(s)+CO2(g). Calcium oxide reacts with silicon dioxide which is a main impurity. CaO(s)+SiO2(s) → CaSiO3(l)

Question 9

What is slag? What happens to it?

Answer 9

Calcium silicate (CaSiO3) It float on top of the molten iron and gets removed

Question 10

Why is Coke burned with oxygen? (equation + state symbols)

Answer 10

In order to react with oxygen and form CO2. C(s)+O2(g) → CO2(g)

Question 11

What happens to carbon dioxide? (Iron extraction stage 2) (equation + state symbols)

Answer 11

At high temperatures carbon dioxide is reduced to carbon monoxide CO2(g)+C(s) → 2CO(g)

Question 12

What happens to carbon monoxide? (Iron extraction part 3) (equation + state symbols)

Answer 12

Carbon monoxide reduces the iron in the haematite. Fe2O3(s)+3CO(g) → 2Fe(l) + 3CO2(g)

Question 13

What is haematite?

Answer 13

Iron oxide Fe2O3

Question 14

What happens to iron as the % of carbon increases? (3)

Answer 14

Cost decreases
Becomes more brittle
It becomes softer

Question 15

When does Iron rust? How can this process be increased?

Answer 15

In presence of water and oxygen. Add salt

Question 16

How to prevent rusting(5)

Answer 16

Paint
Coating Oil or grease
Covered with plastic
Alloying
Galvanising

Question 17

What is Alloying of iron

Answer 17

Adding Chromium and Nickel to make stainless steel

Question 18

What does alloying do?

Answer 18

Provides a strong oxide layer that protects the iron

Question 19

What is Galvanising?

Answer 19

Coating with a layer of zinc

Question 20

Why does Galvanising help?

Answer 20

Zinc is more reactive than iron, so corrodes instead of iron.

Question 21

What is being used to extract aluminium?

Answer 21

Electrolysis

Question 22

What is the overall reaction for extraction of aluminium?

Answer 22

2Al2O3 → 4Al+3O2

Question 23

Aluminium oxide has a very high melting point. What is done to it to reduce it?

Answer 23

Molten cryolite is added

Question 24

What happens to aluminium ions during electrolysis?(electroe equation)

Answer 24

They get attached to cathode and reduced by gaining electrons
AL3+ + 3e- → Al

Question 25

What happens to carbon anodes?

Answer 25

They react with oxygen at high temperatures to produce carbon dioxide and have to be replaced every several days

Question 26

Is pure aluminium strong?

Answer 26

No

Question 27

What are the advantages of Aluminium (7)

Answer 27

Aluminium oxide is strong
It has low density 
Conducts electricity
Resists corrosion 
Has a shiny appearance 
Good strength
Conducts heat

Question 28

What is decomposition?

Answer 28

Breaking down of substance into simpler substances