RICKYtan
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Are there any type of minerals/molecules/elements even solids that when dissolved, in say a glass of room temp water, can raise or lower the temperature? Examples...
mfb said:Nearly everything, and especially salts, will cool the water while getting dissolved.
Roughly half? Okay, then I misremembered it. I know about the hydration, but I expected it to be smaller for most salts.Borek said:Sorry but no. Many salts (and by many I mean something in a "half" ballpark) have quite a large, negative heat of dissolution. My bet is that you are missing the hydration (or more generally solvation) part - capturing of dipole water molecules by cations and anions. That produces quite a lot of heat, especially when dissolving anhydrous salts.
Individual Ion-ion interactions are significantly stronger than the individual ion-dipole interactions in water solutions, but in solution, you have 4-8 waters tightly bound to each ion, and a few dozen more loosely bound to this inner hydration shell structure, so you can pick up energy pretty quickly in these situations.mfb said:Roughly half? Okay, then I misremembered it. I know about the hydration, but I expected it to be smaller for most salts.