An example of an acidic oxide is

1. Analyze the question

The question asks us to identify an acidic oxide from the given list. An acidic oxide is typically a non-metal oxide that reacts with water to form an acid or reacts with a base to form a salt and water.

2. Explain the concept

• Acidic Oxides: These are usually oxides of non-metals (e.g., $SO_2$, $CO_2$, $P_4O_{10}$). When they dissolve in water, they produce acidic solutions.
• Basic Oxides: These are usually oxides of metals (e.g., $Na_2O$, $CaO$, $CuO$). They react with acids to form salt and water.
• Neutral Oxides: These are non-metal oxides that do not react with either acids or bases (e.g., $CO$, $NO$, $N_2O$).
• Amphoteric Oxides: These are oxides that show both acidic and basic properties (e.g., $Al_2O_3$, $ZnO$).

3. Show the solution

Let's evaluate each option:

• A. NO (Nitrogen(II) oxide): This is a neutral oxide. It does not react with water to form an acid, nor does it react with bases.
• B. CO (Carbon(II) oxide): This is also a neutral oxide. It is neither acidic nor basic.
• C. $SO_2$ (Sulfur(IV) oxide): This is a non-metal oxide. When it reacts with water, it forms sulfurous acid: $SO_2(g) + H_2O(l) \rightarrow H_2SO_3(aq)$ Because it forms an acid in water, it is classified as an acidic oxide.
• D. CuO (Copper(II) oxide): This is a metal oxide. It reacts with acids to form salt and water, which makes it a basic oxide.

4. Identify the answer

Based on the analysis, $SO_2$ is the only acidic oxide in the list.

5. Tip

A simple way to remember this for your JAMB exam is the "Non-metal rule": Most non-metal oxides are acidic, while most metal oxides are basic. Just watch out for the "Neutral exceptions" like $CO$, $NO$, and $N_2O$—these three are the most common neutral oxides you will encounter in chemistry exams!