Turner - 4-12-2013 at 15:38
When I put my nose over some HCl and sniff, am I breathing in H+ protons, or Cl-, or HCl molecules (vapor)?
When you have 50% HNO3 solution, is this really a solution of H+ ions combined with NO3- ions and really no HNO3 molecules actually exhist, or does
the disaccosiation of HNO3 take place when it reacts with water into ions and then reform shortly after??
DraconicAcid - 4-12-2013 at 15:53
When you sniff HCl, you are inhaling HCl molecules. Ions do not exist in the gas phase at any reasonable concentration. When these dissolve in the
aqueous mucous of your nose, they dissociate into H+ ions (or hydronium ions, depending on exactly how precise you wish to be) and chloride ions.
If you have 50% aqueous nitric acid, this will be a mixture of hydronium ions, nitrate ions, water, and undissociated nitric acid. The strong acids
are said to dissociate completely, but this is only true for relatively dilute aqueous solutions (and "completely" doesn't mean that there are
absolutely no undissociated molecules, just that the concentration of such molecules is unmeasurably small).
Pyro - 4-12-2013 at 15:55
you are breathing in HCl molecules that dissociate into Cl- and H+ in the moisture of your nose/lungs, but some of it can just be HCl mist
damn, DA, you beat me to it!
[Edited on 4-12-2013 by Pyro]
BlackDragon2712 - 4-12-2013 at 16:01
dissociation only occurs when the hydrogen halide is in contact with a solvent. but since your mucous contains water, that HCl gas would dissociated
and it would acidified your mucous so you would have H3O+ and Cl- ions in your nose. remember that H+ can not exist by itself!!
[Edited on 06/11/2013 by BlackDragon2712]
Turner - 4-12-2013 at 17:00
So then, highly concentrated Nitric Acid (70%) may be 10-50% comprised of actual HNO3 molecules since there is a threshold of how much the HNO3 can
dissaciate in water?
What about anhydrous nitric acid, there is no water to disassociate the HNO3 into ions, so it is purely HNO3 molecules. (which, with no H+ ions,
would be unlike an acid)
Is NaOH even a base if it is totally in solid anhydrous form?
[Edited on 5-12-2013 by Turner]
DraconicAcid - 4-12-2013 at 17:11
In anhydrous nitric acid, there is autoionization (just as water autoionizes); it is still very much an acid. NaOH is a base regardless of whether or
not it is dissolved in water, although the definition of "base" will depend on the solvent system chosen.