Extraction of Metals

Question 1

Ore of zinc?

Answer 1

Zinc Blende (ZnS)

Question 2

Ore of aluminium

Answer 2

Bauxite (Al2O3)

Question 3

Ore of iron

Answer 3

Hematite (Fe2O3

Question 4

Raw materials of a blast furnace:

Answer 4

• haematite
• coke
• limestone (CaCO3)

Question 5

Why is coke used in a blast furnace?

Answer 5

To produce CO to reduce the iron ore

Question 6

Describe the process in a blast furnace

Answer 6

1. Coke burns in the hot air to produce CO2
2. CO2 is reduced to CO
3. CO reduces haematite to iron
4. Limestone undergoes thermal decomposition, producing CaO and CO2
5. CaO combined with SiO2 (sand) to form CaSiO3 (calcium silicate)

Question 7

Describe the extraction process of zinc

Answer 7

1. Zinc blende is heated strongly in the presence of oxygen to convert zinc sulphide to zinc oxide
2. Zinc oxide is reduced with carbon

Question 8

Common forms of metal found naturally?

Answer 8

Metal carbonates/sulphides/oxides

Question 9

What does the anode typically produce?

Answer 9

Nonmetals, or oxygen

Question 10

What does the cathode typically produce?

Answer 10

Metals, or hydrogen

Question 11

What happens during electrolysis?

Answer 11

1. A direct current passes through the electrolyte

2. Electrical energy is changed to chemical energy

Question 12

[cathode] ease of discharge chart

Answer 12

Fluorine
Sulphate
Nitrate
Chlorine
Bromine
Iodine
Hydroxide

Question 13

Common inert electrodes:

Answer 13

• carbon

- platinum

Question 14

Common active electrodes:

Answer 14

Copper, silver

Question 15

How are results different with concentrated electrolytes?

Answer 15

Concentrated ions tend to crowd out other ions, and so obtain preference for discharge.

Question 16

Anions that will never be discharged in electrolysis

Answer 16

Fluorine, sulphate, nitrate, carbonate

Question 17

Cations that will never be discharged in electrolysis

Answer 17

Potassium, sodium, calcium, magnesium, aluminium

Question 18

Why use electroplating:

Answer 18

• improves appearance of a metal

- prevents corrosion of metal

Question 19

What is an electrochemical cell?

Answer 19

A device that converts chemical energy to electrical energy. It consists of electrodes (2 different metals) and an electrolyte solution.

Question 20

How is the anode/cathode determined when electrodes are made of 2 different metals?

Answer 20

The more reactive metal becomes the anode by losing electrons.

Question 28

Define electrolysis:

Answer 28

Breaking down substances using electricity