Answer the following pre **Measuring Energy Changes****Pre-Lab Questions**A sample of lauric acid—an organic compound used to make soap—was heated above its melting point in a test tube and then cooled in a bath of water until it solidified. The temperature of the lauric acid was measured as a function of time and the following graph was recorded.1. What is the physical significance of the flat region (plateau) on the curve?2. Use the graph to estimate the melting point of lauric acid.3. Is heat being absorbed or released by the lauric acid sample as it solidifies?**Materials**- Beakers, 400 mL, 2- Digital thermometer**Graph Explanation**The graph displayed shows the temperature of lauric acid (in degrees Celsius) measured over time (in minutes). The y-axis represents temperature, ranging from 20°C to 70°C. The x-axis represents time, ranging from 0 to 12 minutes. Initially, the temperature decreases steadily until it reaches a plateau, indicating a phase change where the lauric acid solidifies. The plateau is where the temperature stabilizes due to the latent heat of fusion being released.

To determine the melting point of Lauric acid. The physical significance of flat region. Energy is absorbed or release during solidification.1) Lauric acid is heated above the melting point and then solidified.The physical significance of the flat region: lauric acid is foinf to freeze in this region. When time is 2 min the solidification of lauric acid starts and it continue to 12 min until complete solidification occurs. So in 2 min the solidification starts of the sample and after 12 minutes complete solidification of the sample occurs. In this phase change is occuring from liquid to solid, in this process temperature is remains constant during the whole process (Complete solidification). 2) The melting point of lauric acid can be determined by the intersection of the linear region of the cooling portion of the liquid and freezing portion. By intersection the melting point of lauric acid is found 43 Co. 3) The solidification process is exothermic i.e. ∆H is negative in the proces.When lauric acid undergoes solidification process, the temperature will decrease in the whole process. ∆T = negative.As melting requires heat and reverse of it solidification releases energy. So, heat being released bythe lauric acid as it solidifies.