1. **State the problem:** Calculate the energy needed to condense 33.27 g of water vapor at 100°C into liquid water at 100°C. 2. **Formula used:** The energy required for condensation is given by $$Q = m \times L_v$$ where $Q$ is the heat energy (in joules), $m$ is the mass of the substance (in grams), and $L_v$ is the latent heat of vaporization of water. 3. **Important rule:** The latent heat of vaporization of water at 100°C is approximately $2260$ J/g. This is the amount of energy released when 1 gram of water vapor condenses to liquid. 4. **Calculate the energy:** $$Q = 33.27 \times 2260 = 75220.2 \text{ J}$$ 5. **Interpretation:** This means that to condense 33.27 g of water vapor at 100°C, about 75220.2 joules of energy must be removed from the system. **Final answer:** $$Q = 75220.2 \text{ J}$$