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I am trying to compare the electrical conductivity of selected ionic liquids (ILs) and aqueous electrolytes.

By ionic liquid (IL), I mean a pure IL -- no water. Electrical conductivity of ILs is measured in units of Siemens per length. For example, the following table from Leys et al., J. Chem. Phys., 2008 gives the electrical conductivity of selected ILs in units of S/m:

leys

On the other hand, aqueous electrolytes are obviously salts in water. I think, then, electrical conductivity of aqueous electrolytes are concentration-dependent. The following table in the CRC Handbook gives the electrical conductivity of selected aqueous electrolytes in units of S cm^2 / mol:

CRC

How can I compare the electrical conductivities of ionic liquids and aqueous electrolytes?

In other words, is there a way to relate ionic ($\sigma$ in S/m) and molar ($\Lambda$ in S cm^2 / mol) conductivities?

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    $\begingroup$ No, it is an apple to orange comparison. They are changing the frequencies and in the molar conductivity measurements you do not know what was the current frequency. $\endgroup$
    – ACR
    Commented Dec 23, 2020 at 19:48
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    $\begingroup$ What do you want to learn from this comparison? $\endgroup$
    – Karl
    Commented Dec 23, 2020 at 21:06
  • $\begingroup$ @Karl I hope to show that electrical conductivities of aqueous electrolytes are higher than those of ionic liquids (or vice versa). $\endgroup$
    – Andrew
    Commented Dec 23, 2020 at 21:12
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    $\begingroup$ Yes, aqueous electrolytes must be better because acids and bases have the highest molar conductivity known. IL are bulky, viscous, I don't think they are great conductors. $\endgroup$
    – ACR
    Commented Dec 23, 2020 at 22:29
  • $\begingroup$ @M.Farooq How do you think I could quantify that, from results available in the literature? $\endgroup$
    – Andrew
    Commented Dec 24, 2020 at 2:32

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No, it is an apple to orange comparison. Ley et al. are changing the frequencies and in the molar conductivity measurements you do not know what was the current frequency. It is usually measured at 1 kHz if I remember correctly. Similarly, S/m cannot be changed to Scm^2/mol. You can indeed calculate the molarity of pure ionic liquids. The molarity of pure water is ~ 55 M. You should know the moles and the volume of the IL, but there is no point in calculating it.

You need to some heavy literature search. People have actually measured molar conductivity of ILs. Also note that many ILs are not water soluble so you have narrow down your choice and goals. Why are you comparing the conductivities to begin with? See this paper "On the concept of ionicity in ionic liquids" in Phys. Chem. Chem. Phys., 2009, 11, 4962–4967.

Also Walden plot might be useful for you.

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    $\begingroup$ Why not dividing the conductivity of ionic liquid by their molar concentration in the pure state (similar to the famous 55 M for water) ? The unit will be the same as in the equivalent conductivity of electrolytes. $\endgroup$
    – Maurice
    Commented Dec 23, 2020 at 20:16
  • $\begingroup$ @Maurice Then you have the same unit, the comparison still makes no sense. $\endgroup$
    – Karl
    Commented Dec 23, 2020 at 20:25

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