The heat of vaporization of water at 100°C is 40.66 kJ/mol. Calculate the quantity of heat that is absorbed or released when 20.00 g of steam condenses to liquid water at 100°C.

• A. 45.20 kJ released
• B. 22.60 kJ absorbed
• C. 22.60 kJ released
• D. 45.20 kJ absorbed

Answer: (A)

Verified step by step guidance

1. First, identify the process occurring: steam is condensing to liquid water at 100°C. This means heat is released during the condensation process.
2. Determine the molar mass of water (H₂O). The molar mass is calculated as follows: H (1.01 g/mol) * 2 + O (16.00 g/mol) = 18.02 g/mol.
3. Convert the mass of steam (20.00 g) to moles using the molar mass of water. Use the formula: \( \text{moles} = \frac{\text{mass}}{\text{molar mass}} \).
4. Calculate the quantity of heat released using the heat of vaporization. Use the formula: \( \text{heat} = \text{moles} \times \text{heat of vaporization} \).
5. Since the process is condensation, the heat calculated will be released. Ensure to express the final answer with the correct sign indicating heat release.