Topic 4 - Obtaining and using metals (4.1-4.12)

Question 1

What type of reaction are displacement reactions and what occurs during them?

Answer 1

Redox reactions. Therefore reduction (gain of electrons) and oxidation (loss of electrons) occur during these reactions.

Question 2

What do we call highly unreactive metals found in the earth’s crust

Answer 2

Native metals

Question 3

Why is carbon used to extract metals from their oxides

Answer 3

High abundance and cheap

Question 4

How does carbon extract metals from their oxides

Answer 4

Reduction

Question 5

Explain bacterial metal extraction (bioleaching)

Answer 5

Bacteria get energy from the bonds between atoms in the ore, separating the metal from the ore in the process. The leachate contains metal ions which can then be extracted via displacement or electrolysis if the metal is more reactive than carbon.

Question 6

How does phytoextraction ocur

Answer 6

Plants are grown in soil that contains metal compounds. Plants are unable to get rid of these metals so they gradually build up in the leaves. The plants can be harvested, dried and burned in a furnace. The ash contains metal compounds where the metal can be extracted via displacement reactions or electrolysis if the metal is more reactive than carbon

Question 7

Explain the economic benefits of recylcing

Answer 7

• Extracting materials often requires more energy than recycling, so recycling saves money.
• It also creates jobs, materials can e transported and processed into new products.

Question 8

Why is recycling important (environmental)

Answer 8

• It is important to recycle rare materials.
• Saves energy.
• Fossil fuels are running out

Question 9

Devise the experiments that can be done to determine the order of reactivity of metals

Answer 9

Place separate pieces of each metal into solutions of each salt. Observe changes in appearance. The more reactive metal will show the greater number of reaction