How can the purity of benzene be determined using the freezing point method? What are the specific steps?

A specialized glass measuring cup is available for purchase. From memory, its diameter is about 5-6 centimeters and its height is about 6-7 centimeters; it has an outer cup and an inner tube, the diameter of the inner tube being around 1.5 centimeters. The inner tube and the outer cup are not connected to each other. Place the molten phenol into the inner tube, then insert a glass thermometer with a narrow range. Bend a thin wire into a circle with a handle; this circle is placed around the thermometer, its diameter being large enough to fit easily inside the inner tube. During the measurement, the measuring cup is held with the left hand, while the wire is pulled up and down with the right hand – this serves to cool the phenol slowly. When solid appears in the phenol, the reading on the thermometer at that moment represents the measured freezing point. Over time, there might be some inaccuracies in memory; it’s better to rely on manuals or books. Moreover, there might be better instruments available now.

To add to what I wrote yesterday, regarding that glass measuring cup, its product name might be something like freezing point determination cup or similar. Its front view looks like the character for \"concave\"; you can imagine it that way.

3# DXJ122 Thank you. By the way, what’s the name of that book? I’ll go buy it and take a look