 In this experiment, you're going to plot the cooling curve for T-butanol. My calculator has been loaded with the heat program and has been started. And I've set the heat program to record the temperature at 20 second intervals. I'm going to start the calculator. I've put my CBL temperature probe into the T-butanol. It is in a hot water bath, and we can see that the T-butanol is boiling. I'm going to let it collect two or three data points to establish the boiling point of the T-butanol. The graph should be level at this point in time because the temperature is constant as long as there's any liquid T-butanol present. We'll now replace the warm water bath with a cool water bath. We can see that the temperature is starting to fall. The liquid has also stopped boiling. I will gently stir the liquid to try and maintain a uniform temperature in the liquid as it cools. As the temperature approaches the freezing point of the T-butanol, the graph starts to level off. The temperature will remain constant until all the T-butanol has frozen.