Consider a substance X with a ∆Hvap = 20.3 kJ/mol and ∆Hfus = 9.0 kJ/mol. The melting point, freezing point, and heat capacities of both the solid and liquid X are identical to those of water.
a. If you place one beaker containing 50 g of X at 10°C and another beaker with 50 g of H2O at 10°C on a hot plate and start heating them, which material will reach the boiling point first?
b. Which of the materials from part a, X or H2O, would completely boil away first?
c. On a piece of graph paper, draw the heating curve for H2O and X. How do the heating curves reflect your answers from parts a and b?