Abstract In a recent article entitled “Solubility Parameter of Carbon Dioxide–an Enigma” [1] , Marcus reported the literature values for the solubility parameter of liquid carbon dioxide (CO2) at 298 K with discrepancies as large as 200%. An analogous article on ionic liquids has also been published [2] , entitled: “Chameleonic Behavior of Ionic Liquids and Its Impact on the Estimation of Solubility Parameter”. Marcus [1] attempted to resolve this “enigma” for the total solubility parameter of liquid CO2, but much remains to be clarified. Similarly, much remains to be clarified in the second article on ionic liquids [2] . In the present work, the very concept of the solubility parameter is critically examined via a simple and consistent equation-of-state approach. It is demonstrated that the solubility parameter “enigma” can be resolved with such an approach and the potential sources of discrepancies in its estimation can be identified. The implications of this approach on a multitude of practical and theoretical applications are discussed.

中文翻译：

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二氧化碳和离子液体的溶解度参数：它们是一个谜吗？

摘要 在最近一篇题为“二氧化碳的溶解度参数——一个谜” [1] 的文章中，Marcus 报道了液态二氧化碳 (CO2) 在 298 K 下的溶解度参数的文献值，其差异高达 200%。一篇关于离子液体的类似文章也已发表[2]，标题为：“离子液体的变色龙行为及其对溶解度参数估计的影响”。Marcus [1] 试图解开液态 CO2 总溶解度参数的“谜”，但仍有许多问题有待澄清。同样，关于离子液体的第二篇文章 [2] 中还有很多有待澄清。在目前的工作中，溶解度参数的概念通过简单且一致的状态方程方法进行了严格的检查。事实证明，溶解度参数“谜”可以用这种方法解决，并且可以确定其估计中的潜在差异来源。讨论了这种方法对大量实际和理论应用的影响。