When a piece of wood is burned in a campfire, which of the following best describes the chemical process that occurs?

• A. The wood dissolves in the air, forming a homogeneous mixture.
• B. The wood undergoes combustion, producing carbon dioxide and water vapor.
• C. The wood is converted entirely into oxygen gas.
• D. The wood melts and forms a liquid without any chemical change.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the nature of the process described. Burning wood is a chemical change, not a physical one, so options involving dissolving or melting without chemical change can be ruled out.
2. Step 2: Recall that combustion is a chemical reaction where a substance reacts with oxygen, typically producing carbon dioxide and water vapor as products when organic materials like wood burn.
3. Step 3: Recognize that wood is primarily composed of cellulose, a complex carbohydrate, which reacts with oxygen in the air during combustion.
4. Step 4: Write the general combustion reaction for cellulose (simplified as C₆H₁₀O₅) reacting with oxygen: \(\text{C}_6\text{H}_{10}\text{O}_5 + O_2 \rightarrow CO_2 + H_2O\).
5. Step 5: Conclude that the correct description is that the wood undergoes combustion, producing carbon dioxide and water vapor, which is a chemical transformation involving breaking and forming of chemical bonds.