Solubility Decrease with Temperature
Will you please name some ionic compounds whose
solubility decreases when temperature increases other than cerium
(III) sulfate and lithium sulfate?
Ce2(SeO4)3, another cerium salt, shows decreasing
solubility in water as the temperature increases.
So do calcium sulfate (CaSO4) and calcium hydroxide (Ca(OH)2).
source: General Chemistry by Ebbing and Gammon,
(8th ed., Houghton Mifflin, New York, 2005).
Sodium sulfate and cesium sulfate both decrease in solubility with
increasing temperature. In general, the effect of temperature on
solubility is best determined experimentally since there is even no
exact correlation between the sign of enthalpy of solution with
MnSO4.7H2O (not sure about this one)
Lu2(SO4)3.8H2O (essentially all the rare-earth sulfates)
HCl (because it evaporates not crystallizes; gas has high entropy)
CO2 likewise; less ionicity.
Ce(III) selenate (toxic, unusual, possibly not helpful)
Calcium: sulfate, selenate, citrate (decimal-slip misprint?),
glycero-phosphate, hypophosphite, isobutyrate, acetate
chromium (III) sulfate?
Barium acetate-hydrate, succinate
There are not to many hot-spots, for casual crystal-growing uses.
Some good ones probably merely do not have enough published data to
look it up.
Rare eaths and, not so much, transition metals help.
It looks like complex anions help.
So check out some iodates, permanganates, dichromates, phosphates
and organic anions.
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Update: June 2012