D<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}-->iscover that the melting and freezing points of a substance are the same by plotting heating and cooling curves. Students melt and freeze lauric acid and observe through these examples of physical change that the temperature is constant as a substance changes state. Students are given the true melting point of lauric acid and calculate the percent error of their result. Concepts covered include heat of fusion, physical and chemical changes, and the difference between heat and temperature. Compared to the traditional melting point lab that uses water, this experiment has the advantage that most students do not know the melting point of lauric acid. All materials are reusable and are sufficient for 30 students working in 10 groups of 3.