Barium hydroxide, fractionation using

H. M. Dawson and J. McCrae, D. P. Konowaloff, and W. Gaus also used soln. of various salts of the alkali metals, and of potassium, sodium, cupric, or barium hydroxide in place of water and also copper sulphate, copper chloride, zinc sulphate, and cadmium iodide while M. 8. Sherrill and D. E. Russ examined the effect of ammonium chromate. W. Herz and A. Kurzer examined the distribution of ammonia between water and a mixture of amyl alcohol and chloroform. Observations on the distribution of ammonia between water and chloroform were made by T. S. Moore and T. F. Winmill, G. A. Abbott and W. C. Bray, and J. M. Bell. J. H. Hildebrand gave for the molar fraction N X104 of ammonia at 1 atm. press., and 25°, dissolved by ethyl alcohol, 2300 methyl alcohol, 2730 and water, 3300. 

Ioffe and Sorokin (1954) investigated a novel procedure for the hydrolysis of elastin using copper sulfate and 0.4 N barium hydroxide at 37°C for 60 hr. The first product of hydrolysis was a protein which resembled a-elastin in that it showed reversible coacervation on raising the temperature. This substance was subsequently degraded further to yield a soluble fraction and a fraction containing peptides. Alkaline hydrolysis was much more rapid in the presence than in the absence of copper ion. 

The equilibrium of a solvation reaction has its own equilibrium constant called the solubility product Ksp. Use Ksp the same way you would use any other equilibrium constant. Remember that solids and pure liquids have an approximate mole fraction of one and can be excluded from the equilibrium expression. Thus, solids are left out of the solubility product expression as in the example of the Ksp for barium hydroxide shown below. 

Acetone is sufficiently reactive to pose serious problems if it needs to be recovered to a high purity by distillation. Some commonly used inorganic dehydrating agents such as activated alumina and barium hydroxide, and also mildly acidic conditions, can accelerate acetone s condensation when warm to diacetone alcohol, which can in turn dehydrate to yield mesityl oxide. Not only can this cause a loss of acetone from a fractionating system (since both of these derivatives of acetone are high boiling) but it increases the amount of water that may need to be removed in the recovery. 

A typical procedure for the isolation of the free bile acids included precipitation of the bile protein with alcohol and hydrolysis of the conjugated acids for long periods of time in from 5 to 10 percent aqueous sodium hydroxide. Different methods were then applied for the isolation of each individual acid from the resulting crude mixture of free bile acids. Cholic and deoxycholic acid could be separated from each other by the addition of concentrated barium chloride to an ammoniacal solution of the hydrolyzed acids, since most of the barium deoxycholate is precipitated with the fatty acids, whereas barium cholate remains in solution (34). The greater solubility of chenodeoxycholic acid in ether was used by Wieland for its isolation lithocholic acid, the weakest of the acids, was obtained by fractional precipitation... 

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