Extracting Unreactive Metals

Unreactive metals like gold, silver and copper are often found in the Earth’s crust as pure metals, as they do not easily react with other elements.
These pure metals are typically extracted from the Earth through mining.
Gold and silver are usually found in veins or in nuggets. Once mined, they can be purified further through a process called smelting if necessary. This process involves melting the metal and removing impurities that rise to the surface.
Copper can also be found as pure copper, but it is often found in ores such as copper sulphide.
To extract copper from copper sulphide, you need to heat the ore in air. This causes the copper sulphide to react with the oxygen in the air to form copper(I) oxide and sulphur dioxide.
The copper(I) oxide is then reduced by carbon in a smelter. The resultant pure copper is then collected.
All these extraction methods can have significant environmental impacts. Mining can lead to habitat destruction and pollution, while smelting produces gases that can contribute to air pollution.
It’s also worth noting that unreactive metals are finite resources. This means that they can run out if we continue to extract them at current rates. Hence, recycling of these metals is encouraged to conserve these precious resources.
The principles behind these extraction methods are examples of redox reactions, where one substance is reduced (gains electrons) and another is oxidised (loses electrons).
The reactivity series of metals can guide us in predicting which metals can be found as pure elements and which need to be extracted from its ores. Unreactive metals are usually found at the bottom of this series.
Reviewing this information regularly can help ensure you feel confident and prepared. It’s also a good idea to practise applying this knowledge with past paper questions to understand how to approach different types of questions.