In the overall equation for photosynthesis in plants, how many molecules of water (\(\mathrm{H_2O}\)) are required to produce one molecule of glucose (\(\mathrm{C_6H_{12}O_6}\))?

• A. 18
• B. 6
• C. 12
• D. 1

Answer: (B)

Verified step by step guidance

1. Step 1: Recall the overall balanced chemical equation for photosynthesis: 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂. This equation represents the process by which plants convert carbon dioxide and water into glucose and oxygen using sunlight.
2. Step 2: Identify the stoichiometric relationship between water (H₂O) and glucose (C₆H₁₂O₆) in the equation. For every 1 molecule of glucose produced, 6 molecules of water are required.
3. Step 3: Understand that the water molecules are used during the light-dependent reactions of photosynthesis to provide electrons and protons, which are essential for the synthesis of glucose.
4. Step 4: Verify the ratio by analyzing the balanced equation. The coefficients in the equation indicate the exact number of molecules involved in the reaction. Here, 6 molecules of water are explicitly required to produce 1 molecule of glucose.
5. Step 5: Conclude that the correct answer is based on the stoichiometry of the balanced equation, which shows that 6 molecules of water are required to produce 1 molecule of glucose.