Ionic ratio hypothesis

Increasing KC1 concentration lowers inhibition as shown in Table II. The fact that damage increased with KC1 concentration is consistant with the ionic ratio hypothesis and suggests a base exchange mechanism whereby calcium ions are more easily extracted from the clay and replaced by potassium ions as the potassium concentration increases. 

All four compounds were found to be potent antagonists at /u, and S receptors in the MVD and were devoid of agonist actions. This was reflected in their in vitro receptor binding characteristics. Loew and Berkowitz(268) had postulated that strict steric requirements for the OH-N interaction with a common ionic site would be impaired by O-alkylation and that this should result in an enhancement of the agonist-antagonist ratio. The lack of agonist actions in the 14/3-alkylated derivatives is evidence in contradiction of the common ionic site hypothesis. 

In order to validate the hypothesis mentioned above, the Ni retention capacity of the Lac Tio waste rock was estimated using a batch sorption test performed on a fresh (C1) and weathered (C4) sample, followed by a 3-step Sequential Extraction Procedure (or SEP). The batch sorption test was done using a 10 mg/L Ni solution with an initial pH of 6, an ionic force adjusted to 0.05 M with NaN03 and with a liquid/solid ratio of 25. Some of the batch sorption results are presented in Figure 3. 

More O Ferrall (personal communication) has recently studied solutions of sodium methoxide in MeOH and MeOD (with a little MeOH) by the NMR method and has derived a fractionation factor for the methoxide ion which must, of course, be due to methanol molecules associated with the solute. This factor is quite far from unity (0-72) and thus emphasizes the importance of lyate-solvent hydrogen bonds, and adds plausibility to the hypothesis of the importance of hydrogen bonding to the aqueous hydroxide ion in connection with hydrogen isotope fractionation in the hydroxide ion. However, it has not yet been shown that the methoxide fractionation is independent of the nature of the cation, and detailed analyses based on this number may be premature. It will be evident that secure knowledge of this parameter and of the fractionation factor of the methanolic hydrogen ion will in due course allow prediction of the ionic product of MeOD relative to that for MeOH and also of ratios for some acids in methanol... 

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