Question

24) What role does Acidithiobacillus ferrooxidans play in the copper leaching process?

A) oxidation of sulfide to sulfate
B) reduction of oxidized iron (Fe3+) to reduced iron (Fe2+)
C) oxidation of reduced iron (Fe2+) to oxidized iron (Fe3+)
D) reduction of sulfate to sulfide

Answer 1

Acidithiobacillus ferrooxidans oxidizes reduced iron (Fe2+) to oxidized iron (Fe3+), which is a key step in the copper leaching process, aiding in the extraction of copper from metal sulfides.

Step-by-step explanation:

Acidithiobacillus ferrooxidans plays a crucial role in the copper leaching process by oxidizing reduced iron (Fe2+) to oxidized iron (Fe3+). This bacterium uses the energy derived from the oxidation of iron and sulfur compounds to grow, and this activity is essential to the bioleaching process. In the presence of Acidithiobacillus ferrooxidans, the sulfur in metal sulfides, such as copper sulfide, is transformed into sulfate, facilitating the extraction of copper.

Given the reaction provided, it can be further understood that the oxidation of Fe2+ to Fe3+ by the bacterium makes Fe3+ available to act as an oxidizing agent for metal sulfides in the leaching process. Therefore, the correct answer is C) oxidation of reduced iron (Fe2+) to oxidized iron (Fe3+) in the context of the copper leaching process.