1. to investigate the heating process for solid dodecanoic acid
2. to investigate the cooling process for liquid dodecanoic acid
3. to determine and compare the melting and freezing points of dodecanoic acid
SUPPLIES:
Equipment
ring stand buret clamp hot plate test tube (18mm * 150 mm) assembly (half full with solid dodecanoic acid with thermometer embedded) beaker (400 mL) thermometer for water bath lab apron safety goggles
Chemical Reagents dodecanoic acid, C11H23COOH (in test tube apparatus)
Part I: The Heating Process We need to put on the lab apron and safety goggles before we do anything. Then we need to choose a partner and decide what role we are performing in Part I. One of us needs to be an observer, and the other will be the recorder. Later we will change our roles in Part II. The recorder need to record the temperature so then we can right the data in table I. while doing the lab, we need to obtain a test tube assembly consisting of a thermometer embedded in solid dodecanoic acid from Mr. Morrison. We need to remove the cotton plug and save it for the end of the lab. To do the lab, we need to put 300 mL of tap water into a 400 mL beaker and place the beaker on the hot plate. Then we need to turn the hot plate on to high heat and raise the temperature to around 55C to 60C, and we can measure the water temperature by using a thermometer. While the water is heating, we need to set up a ring stand with a buret clamp to hold the test tube assembly. When the water has reached to 55C, we need to turn the hot plate to a low heat. Then, we will lower the test tube assembly into the water bath and clamp in position so that all the dodecanoic acid is submerged below the water line. After that, the recorder can record the temperature of the dodecanoic acid in Table1, and every 30 s after that. During the heating process, the temperature of the water bath should be monitored with its thermometer to make certain that the water