Consider the following statements: 1. Steam at 100°C and boiling water at 100°C contain the same amount of heat. 2. Latent heat of fusion of ice is equal to the latent heat of vaporization of water. 3. In an air-conditioner, heat is extracted from the room air at the evaporator coils and is rejected out at the condenser coils. Which of these statements is/are correct?

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YESPYQ · Accepted Answer

Correct answer: Only 3. Statement 1 is incorrect: Steam at 100°C contains significantly more heat than boiling water at 100°C. This is because steam has absorbed additional energy in the form of latent heat of vaporization which is the energy required to convert water at 100°C into steam at the same temperature without changing its temperature. Statement 2 is incorrect: The latent heat of fusion of ice (the energy required to convert ice at 0°C to water at 0°C) is approximately 334 kJ/kg while the latent heat of vaporization of water (the energy required to convert water at 100°C to steam at 100°C) is approximately 2260 kJ/kg. Statement 3 is correct: In an air-conditioner the refrigerant absorbs heat from the room air at the evaporator coils and cools the air. This heat is then transported to the condenser coils, where it is released to the outside environment. This process is based on the principles of thermodynamics and the refrigeration cycle. 245

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