The micronutrient iron is abundant in soil but often unavailable to plants due to insolubility. Knowing that the reaction Fe(OH)3 + 3 H+ ↔ Fe3+ + 3 H2O occurs, and assuming all soil samples have the same total amount of iron, which type of soil would you predict to have the highest amount of soluble iron?

Question

Quizplus · Accepted Answer

The reaction given shows that the solubility of iron increases with increasing acidity (i.e. decreasing pH), so acidic soil (choice B) would have the highest amount of soluble iron. Neutral soil (choice A) and alkaline soil (choice C) would have lower solubility of iron. Therefore, B is the best choice. D is also incorrect as it contradicts the given reaction.

The Micronutrient Iron Is Abundant in Soil but Often Unavailable