To find out how much heat is emitted when 4.55 g of water condenses, we first need to convert the mass of water into moles. We can do this using the molar mass of water, which is approximately 18.015 g/mol.
First, calculate the number of moles of water:
Number of moles = Mass (g) / Molar mass (g/mol)
Number of moles = 4.55 g / 18.015 g/mol ≈ 0.252 moles.
Next, we use the heat of vaporization to determine the heat emitted during condensation. The heat emitted when 1 mole of water condenses is equal to the heat of vaporization, which is 44.0 kJ/mol.
Now, we can calculate the total heat emitted:
Heat emitted = Number of moles × Heat of vaporization
Heat emitted = 0.252 moles × 44.0 kJ/mol ≈ 11.088 kJ.
Therefore, the heat emitted when 4.55 g of water condenses at 25 degrees Celsius is approximately 11.09 kJ.