8.87. Natural Weathering of Ores Iron is oxidized in a number of chemical weathering processes. How many moles of O2 are
consumed when one mole of magnetite (Fe3O4) is converted
into hematite (Fe2O3)?

0.25 mole of O₂.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

4Fe₃O₄ + O₂ —> 6Fe₂O₃

From the balanced equation above,

4 moles of Fe₃O₄ reacted with 1 mole of O₂.

Finally, we shall determine the number of mole of O₂ required to react with 1 mole of Fe₃O₄. This can be obtained as follow:

From the balanced equation above,

4 moles of Fe₃O₄ reacted with 1 mole of O₂.

Therefore, 1 mole of Fe₃O₄ will react with = (1/4) = 0.25 mole of O₂.

Thus, 0.25 mole of O₂ is required for the reaction.