Question

Conductivity of li ion in aqueous solution is less than that of cs ion

Answer 1

Diffusion of ions in sea water and in deep-sea sediments

Li Yuan-Hui, Sandra Gregory

Geochimica et cosmochimica acta 38 (5), 703-714, 1974

Abstract The tracer-diffusion coefficient of ions in water, D j 0, and in sea water, D j∗, differ by no more than zero to 8 per cent. When sea water diffuses into a dilute solution of water, in order to maintain the electro-neutrality, the average diffusion coefficients of major cations become greater but of major anions smaller than their respective D j∗ or D j 0 values. The tracer diffusion coefficients of ions in deep-sea sediments, D j, sed., can be related to D j∗ by D j, sed.= D j∗· α θ 2, where θ is the tortuosity of the bulk sediment and aa constant close to …

View at sciencedirect.com

Cited by 2602

Related articles

All 6 versions

jgp.rupress.org

Negative conductance caused by entry of sodium and cesium ions into the potassium channels of squid axons

Francisco Bezanilla, Clay M Armstrong

The Journal of General Physiology 60 (5), 588-608, 1972

Internal Cs+, Na+, Li+, and, to a lesser degree, Rb+ interfere with outward current through the K pores in voltage clamped squid axons. Addition of 100 mM NaF to the perfusion medium cuts outward current for large depolarizations about in half, and causes negative conductance over a range of membrane voltages. For example, suddenly reducing membrane potential from +100 to +60 mv increases the magnitude of the outward current. Internal Cs+ and, to a small extent, Li+, also cause negative conductance. Na+ ions permeate at least 17 times less well through the K pores than K+, and Cs+ does not permeate measurably. The results strongly suggest that K pores have a wide and not very selective inner mouth, which accepts K+, Na+, Li+, Cs+, tetraethylammonium ion (TEA+), and other ions. The diameter of the mouth must be at least 8 A, which is the diameter of a TEA+ ion. K+ ions in the mouths probably have full hydration shells. The remainder of the pore is postulated to be 2.6–3.0 A in diameter, large enough for K+ and Rb+ but too small for Cs+ and TEA+. We postulate that Na+ ions do not enter the narrower part of the pore because they are too small to fit well in the coordination cages provided by the pore as replacements for the water molecules surrounding an ion.