Determination of the single-ion activities of H+ and Cl- in aqueous hydrochloric acid solutions using an ionic liquid salt bridge
Determination of the single-ion activities of H+ and Cl- in aqueous hydrochloric acid solutions using an ionic liquid salt bridge
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使用离子液体盐桥测定盐酸水溶液中 H 和 Cl- 的单离子活度
DOI：
10.1021/jp2052079
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
Takashi Kakiuchi
中科院分区：
文献类型：
--
作者：
Hideaki Sakaida;Takashi Kakiuchi
本文用离子液体盐桥法测定了浓度高达500 mmol·dm-3 HCl的盐酸水溶液中H+和Cl-的单离子活度，在25 °C时，log_（10）γ的95%置信区间为±0.012。这些活动的几何平均值与文献值的平均离子活度的测定与Harned电池的HCl的离子强度高达500 mmol·dm-3。该一致性支持了用于估计单离子活性的假设，即在10和500 mmol·dm-3之间的HCl浓度范围内，离子液体盐桥两侧的液体接界电位保持恒定，在电池电压的置信区间± 1 mV内。在所研究的浓度范围内，H+和Cl-的单离子活度系数值与Fraenkel（Mol. Phys.2010，108，1435; J. Phys. Chem. B 2011，115，557），这一事实在电解质溶液的物理和分析化学中是重要的和隐含的。
Single-ion activities of H+and Cl–in aqueous hydrochloric acid solutions up to 500 mmol·dm–3HCl have been determined, independently of each other, with reasonable accuracy, 95% confidence interval of log10γ being ±0.012 at 25 °C, by use of an ionic liquid salt bridge inserted in a Harned cell. The geometric averages of those activities agree well with the literature values of the mean ionic activity of HCl determined with a Harned cell up to an ionic strength of 500 mmol·dm–3. The agreement supports the assumption used in estimating the single-ion activities, that is, the liquid junction potentials on both sides of the ionic liquid salt bridge stay constant, within the confidence interval of the cell voltage, ± 1 mV, over the concentration range of HCl between 10 and 500 mmol·dm–3. The single-ion activity coefficient values of H+and Cl–over the concentration range studied show fairly good agreement with the recent theoretical predictions by the “smaller-ion-shell” model proposed by Fraenkel (Mol. Phys. 2010, 108, 1435; J. Phys. Chem. B 2011, 115, 557), which fact is significant and implicative in physical and analytical chemistry of electrolyte solutions.