摘要：

P-chlorophenol and p-chlorocresol increase the negative potential of the air/water boundary as a result of the negative electric field of halogen directed to the gaseous phase (permittivity 1). However, the o-isomer of chlorophenol decreases the negative potential owing to saturation of the negative field directed to the aqueous phase (permittivity 80). 6-Fluoroquinoline is a larger molecule; it displaces many oriented water dipoles from the surface, and consequently the pd across the surface is decreased. 6-Methoxyquinoline decreases the potential much more than 6-fluoroquinoline owing to the lack of the fluorine negative dipole. Points of inflexion lying on the curves representing the potential and surface-tension changes vs pH allow an estimation of the dissociation constants of the compounds.

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