【摘要】 本文在25℃下分别测定了正己酸和正庚酸在纯水和小离子盐水溶液中的溶解度.标出了弱酸未解离部分的活度系数f_u,作出氯化锂等八种盐的lgf_u～Cs图,均呈直线关系.计算并比较了乙酸等五种脂肪酸在小离子盐水溶液中的盐效应和盐析常数的各种理论值.更多还原

【Abstract】 The solubility of n-hexanoic acid and n-heptanoic acid at 25℃ was determined respectively in water as well as in the aqueous salt solution. The activity coefficient of the undissociated part of the weak acid fu has also been calculated,When we ploted log fu vs. Cs for eight salts, the results obtained are all straight-lines. By comparison of the Salt effect of five aliphatic acid in the aqueous solutiion for the salts with small ions, the. salting-out order is C6H15COOH> C5H14COOH>G5H7COOH>C2H5COOH>CH3COOH for each salt.We have calculated the salting-out constants of these acids in the solutions of alkaline halides by the formulas of (1) Debye-McAulay, (2) McDevit-Long, (3) Conway-Desnoyers-Smith and (4) Scaled Partical Theory. With the exception of the lithium salts, they all give the right salting-out order of the salts, but the formulas (3) and (4) give the results in better agreement with the experiment than those of (1) and (2).更多还原