The process of rusting is an example of the formation of

Analysis of the Question

The question asks for the chemical classification of the product formed when iron undergoes the process of rusting.

Concept Explanation

Rusting is the corrosion of iron in the presence of oxygen and moisture. Chemically, iron reacts with oxygen to form hydrated iron(III) oxide, represented by the formula: $Fe_2O_3 \cdot xH_2O$

To classify this oxide, we look at the nature of the metal involved. Iron is a transition metal. Generally:

• Basic oxides are formed when metals react with oxygen (e.g., $Na_2O$, $MgO$, $Fe_2O_3$). They react with acids to form salt and water.
• Acidic oxides are formed when non-metals react with oxygen (e.g., $CO_2$, $SO_2$).
• Amphoteric oxides show both acidic and basic properties (e.g., $Al_2O_3$, $ZnO$).

Since iron is a metal, its oxide ($Fe_2O_3$) acts as a base. It reacts with acids (like dilute $HCl$ or $H_2SO_4$) to produce iron salts and water, confirming its basic nature.

Step-by-Step Solution

1. Identify the reaction: Rusting is the oxidation of iron: $4Fe(s) + 3O_2(g) + xH_2O(l) \rightarrow 2Fe_2O_3 \cdot xH_2O(s)$.
2. Determine the product: The primary component of rust is iron(III) oxide ($Fe_2O_3$).
3. Classify the oxide: Iron(III) oxide is an oxide of a metal. Metal oxides are typically basic in nature because they react with acids to form salts.
4. Conclusion: Therefore, the formation of rust is the formation of a basic oxide.

Exam Tip

Remember the "Metal-Base, Non-metal-Acid" rule:

• Metal oxides = Basic (think MB - "My Brother").
• Non-metal oxides = Acidic (think NA - "Not Available"). This simple mnemonic will help you classify almost any oxide you encounter in your JAMB Chemistry exam!