Name a metal that exists as an element.
Answer:
Silver and aurum.
Explain why aluminium cannot be extracted through reduction reaction by carbon.
Answer:
– Aluminium is more reactive than carbon in the reactivity series of metals.
– Reaction between aluminium oxide and carbon does not occur.
– Carbon cannot reduce aluminium oxide.
Iron is extracted by using a blast furnace:
(a) Write the chemical equation for a redox reaction that produces molten iron.
(b) What is the function of calcium carbonate in the process of iron extraction?
Answer:
(a) $$
2 \mathrm{Fe}_2 \mathrm{O}_3+3 \mathrm{C} \rightarrow 4 \mathrm{Fe}+3 \mathrm{CO}_2
$$
(b)
– At a high temperature, calcium carbonate, CaCO3 decomposes to form calcium oxide, CaO (quicklime) and carbon dioxide, CO2.
– Calcium oxide, CaO reacts with the impurities in iron ore such as silicone(IV) oxide, SiO2 to form slag or calcium silicate, CaSiO3.
– This reaction is important to separate the impurities from molten iron.
– The difference in density causes slag to be at the top layer of the molten iron that makes the separation process easier.
Name the metal that can be used to extract copper from copper(II) oxide.
Explain your answer.
Answer:
– Zinc (or Magnesium / Aluminium / Iron / Tin / Lead)
– Zinc is more reactive than copper.
– Zinc can reduce copper(II) oxide to copper.