The heat of vaporization for water is 25 ◦C at44.0 kJ mol−1. What is the heat of vaporizationfor water at 100 ◦C?A. greater than 44.0 kJ mol−1B. equal to 44.0 kJ mol−1C. equal to −44.0 kJ mol−1D. less than 44.0 kJ mol−1E. none of these

Why are steam burns so much worse than water burns even if the H2O is at the same temperature for both phases? Hint: Consider the heat of vaporization of water.

The cooling effect of alcohol on the skin is due to its evaporation. Calculate the heat of vaporization of ethanol (ethyl alcohol), C2H5OH. C2H5OH(l)C2H5OH(g);H=? The standard enthalpy of formation of C2H5OH(l) is 277.7 kJ/mol and that of C2H5OH(g) is 235.1 kJ/mol.

Are changes in state physical or chemical changes? Explain. What type of forces must be overcome to melt or vaporize a substance (are these forces intramolecular or intermolecular)? Define the molar heat of fusion and molar heat of vaporization. Why is the molar heat of vaporization of water so much larger than its molar heat of fusion? Why does the boiling point of a liquid vary with altitude?