CHM 100 – Introduction to Chemistry

Experiment # 6 – Change of State

Revised instructions…

Part A:  Cooling Curve

1) Work with a partner for this lab.

2) Obtain a test tube of “lauric acid + thermometer set-up” from the side counter and immerse it in the communal boiling water bath on the side counter.  Heat until the temperature of the lauric acid is approximately 55ºC (or until it has liquefied).

3) Quickly suspend this test tube using a utility clamp and ring stand. 

4) Do NOT stir or disturb the lauric acid as it cools.  When the temperature of the lauric acid drops to 48ºC, record the temperature every 30 seconds.  Record temperature/time data until the lauric acid solidifies or until the temperature is about 36°C (about 30 minutes). 

5) Leaving the thermometer in the now solid lauric acid, return this “lauric acid + thermometer set-up” to the side counter.  Do NOT pour the lauric acid down the sink drain.

6) Plot a cooling curve of temperature vs. time

Part B:  Melting Points

     OMITTED

*** Please return this sheet to your lab instructor at the end of the lab. ***

***  Thank you!  ***