Heating And Cooling~

THE HEATING PROCESS ~

1. Put on your safety equipment.

2. One partner will as observer, the other will act as recorder. Recorder is responsible for stating the 3os intervals when temp. readings are to be taken. Prepare the table for experimental result.

3. Obtain a test tube assembly consisting of a thermometer endedded in solid dodecanotic acid and remove the cotton plug and save it for the end of experiment.

4. Put 300mL of tap water in a 400mL beaker and place the beaker on a hot plate. Turn it on to high heat and raise the temp. of water bath between 55 and 60. Monitor the water temp. with thermometer. While the water is heating, set up a ring stand withg a buret clamp to hold the test tube.

5. When the water bath reached 55, turn the hot plate to low heat. Lower the test tube into the water line. Record the temp. of dodecanoic acid and every 30s after that. During the heating process, the temp. of water bath should be monitored with its thermometer to make certain that the water temp. remains above 55.

6. Continue temp. recording until the temp. above 50. As the dodecanoic melts, stir it gently to mix the solid and liquid. Record the times when melting begins and ends, as well as observations.

7. Turn off the hot plate.

THE COOLING PROCESS~

1. Require teamwork, table 1 will be continued to read.

2. Raise the test tube out of the hot water bath and clamp it in position in room temp.. Just replace the hot water in beaker with room temp.

3. Immediately start monitoring the cooling process. Record the temp. of liquid dodecanoic acid

4. Record the temp. of dodecanoic acid every 30s until the temp. is near 25. Record when solidification begins and ends , as well as observations.

5. When the temp. at or near 25, stop recording temp. readings.

6. Reset the test tube with cotton plug. Return the test tube to your instructor and put away all your equipment.
7. Wash your hand with soap and water.