Salting Out Parameter Determination by Randall and Failey

In the second paper of their series (S29), Randall and Failey found similar results for the noneleotrolytes iodine, phenylthiourea and o-nitrobenzaldehyde. 

The last paper (S30) presented activity coefficients for the undissociated part of the following weak electrolyte acids benzoic, ortho toluylic, salicylic, ortho-nitrobenzoic, acetic, monochloracetic and dichloracetic acids. In a study of binary solutions of sodium and potassium acetate. RandaU. McBain and White (S26) found the ionic activity coefficients to be very close in value to the ionic activity coefficients for binary sodium and potassium chloride solutions. Consequently, in Randall and Failey s paper on the activity coefficients of the undissociated part of weak electrolytes, the activity coefficients of the monobasic acids in salt solutions oi varying concentrations were assumed to be equal to the activity coefficient of hydrochloric acid in the same or similar salt solution at the same concentration. This meant that  

Randall and Failey felt that, while not completely accurate, such assumptions could be safely made for such dilute solutions and would not have much effect on the calculations for the activity coefficients of the undissociated portion the weak electrolyte acid. 

The activity coefflcients of the undissociated portions of the weak acids were calculated in the following manner using data presented by numerous authors of the solubility of the weak acid in salt solutions of varying concentrations  

Since the activity of the weak acid in a solution saturated with that weak acid is constant  

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