How does ion size affect conductivity?

1 Answer
Apr 7, 2014

In general, smaller ions have greater conductivity than larger ions.

Explanation:

Small ions have small areas. There is less resistance as they move through the solution.

For example, in molten salts, the conductivity of "Li"^+ is greater than that of "Cs"^+.

Small ions have high charge density.

In aqueous solutions, this gives them a large hydration shell that moves with them.

For example, hydrated "Li"^+ ions are larger than hydrated "Cs"^+ ions.

Thus, aqueous solutions of lithium salts have lower conductivities than those of cesium.

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