Chapter 12, Problem 35PS

Benzene, C₆H₆, is an organic liquid that freezes at 5.5 °C (Figure 11.1) to form beautiful, feather-like crystals. How much energy is evolved as heat when 15.5 g of benzene freezes at 5.5 °C? (The enthalpy of fusion of benzene is 9.95 kJ/mol.) If the 15.5-g sample is remelted, again at 5.5 °C, what quantity of energy is required to convert it to a liquid?