Question

Which of the following statements about freeing metals from their ores is true?

1) Vitamin C removes metal from its ore by inhibiting air oxidation.
2) Coke or coal can be used to remove a metal from its ore.
3) Hydrogen cannot be used to remove metal from its ore because it is an oxidizing agent.
4) Other metals cannot be used to remove a metal from its ore.

Answer 1

The correct answer is that coke or coal can be used to remove a metal from its ore, a process known as smelting. Coke serves as the reducing agent in the extraction of iron from iron ore in a blast furnace.

Step-by-step explanation:

The true statement about freeing metals from their ores is 'Coke or coal can be used to remove a metal from its ore'. The process of extracting metals from their ores is known as smelting, which involves using heat and a chemical reducing agent, typically a source of carbon like coke or coal, to decompose the ore and extract the metal.

For instance, in the smelting of iron ore in a blast furnace, coke acts as the reducing agent where the following reaction takes place:

2Fe2O3 + 3C → 4Fe + 3CO2

Other methods of extraction include electrolysis, which is used for metals that are too reactive, like aluminum, where using carbon would require uneconomic temperatures.