Phase boundaries in ternary systems of sodium oleate, compared with other soaps

Summary

1. The boundaries of isotropic solutions of sodium oleate containing salt have been determined over a series of temperatures. Prolonged heating in glass tubes alters sodium oleate solutions, rendering the soap less soluble.

2. It is found that when sodium silicate replaces sodium chloride in the same percentage by weight the sodium oleate is not salted out, but tends on cooling to set to a clear jelly.

3. The phase boundaries for soap solutions containing chloride have been assembled and recalculated to the same units for comparison with each other and with the results for soaps made from a few single commercial oils and fats. In spite of its solubility in water, sodium oleate is readily salted out by electrolytes.

4. The effect of small amounts of salt such as are retained in commercial soap systems upon the boundaries of the strict binary phase diagram have been determined.