# Why does the thermal conductivity of water decrease with increasing salinity?

Intuitively I would expect the thermal and electric conductivity to be positively related, and since electric conductivity increases with salinity, so should thermal. But according to this table (p.10) it decreases. Why is this?

Related: is there such a thing as the Wiedemann-Franz law for liquids like water?

There's a paper that has theoretical derivations about it, but it's nowhere to be found:
Predvoditelev, A. S., "Some invariant Quantities in the Theories of Heat Conductance and the Viscosity of Liquids," Russian Journal of Physical Chemistry, Vol. 22, p. 339 (1948)

• Someone correct me, if I am wrong, but doesn't the expectation that thermal conductivity and electrical conductivity are correlated come from the special case of metal physics, where electron transport is the main source of both (in a certain temperature range)? There are marvelous counterexamples, for instance diamond, sapphire and pure crystalline silicon, which have enormous thermal conductivity, but very poor or basically non-existent electrical conductivity. – CuriousOne Aug 12 '14 at 18:57
• @CuriousOne, yes this confuses me also, yet i too have seen cases where the 2 are not correlated as such – Nikos M. Aug 12 '14 at 19:05
• @CuriousOne yes, that is what I based my expectation on. I agree that it's a bit loose to tie metals and saline liquids together like that. – Jan M. Aug 12 '14 at 19:12
• I completely misread the question. Somehow I read it as asking about specific heat. I'm withdrawing my answer, and then later I'll withdraw this comment. – David Hammen Aug 13 '14 at 0:24