Tetrachloroethane, physical properties

There are striking differences in physical properties between the atactic and isotactic forms. The atactic material is soft, elastic, somewhat sticky, and rather soluble in solvents such as 1,1,2,2-tetrachloroethane. Isotactic polypropene is a hard, clear, strong crystalline polymer that melts at 175°. It is practically insoluble in all organic solvents at room temperature, but will dissolve to the extent of a few percent in hot 1,1,2,2-tetrachloroethane. That the difference between the atactic and isotactic polymers arises from differences in the configurations of the methyl groups on the chains is shown in a... 

For analysis of the samples, a physical method is often preferable to chemical methods. Chemical analysis nsually is appropriate only when a simple titration of each sample is involved, as in the case of the system HCI-H2O. If a physical property is chosen as the basis for an analytical method, it should be one that changes significantly and smoothly over the entire composition range to be studied. The refractive index is one property that can be used for the cyclohexanone-tetrachloroethane system. The values of are 1.4507 for cyclohexanone and 1.4942 for 1,1, 2,2 -tetrachloroethane, and log is almost a linear... 

---