Sodium octanoic acid, solubility

Add each to an aqueous solution of sodium bicarbonate, NaHCC>3. Only the octanoic acid will react with this solution. It will dissolve in aqueous NaHC03 as a water-soluble salt with the evolution of carbon dioxide. There will be no reaction with ethyl octanoate. 

Sodium octanoate is the water soluble sodium salt of octanoic (caprylic) acid, but it has no antibacterial or antifungal activity as tested by the same procedures described above, and the results are reported in Table 4.12. 

Figure 6. The solubility of water (weight percent of total) in sodium octanoate (S)/octanoic acid (A) --) and sodium octanoate (S)/octanol (A) (---) mix-...

If the third component is a water-insoluble alcohol (five carbons or more), amine, carboxylic acid, or amide, the phase topography is profoundly modified. The phase diagram shown in Figure 3.8b [7] shows in addition to LI and HI a very large lamellar phase, a narrow reverse hexagonal phase H2, and, even more important, a sector-like area of reverse micelles L2. This means that the solubility of n-decanol in a sodium octanoate-water mixture containing between 25 and 62% amphiphile is far more important (30 to 36%) than pure water (4%) and pure sodium octanoate (almost zero). This phase is essential to obtain water-in-oil (w/o) microemulsions. 

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