Ever heard of Concentrated Vinegar removal process

[g_axelsson]

which one is real?
i read when your mix acetic acid and salt you make sodium acetate and hcl and i read the opposite that adding hcl to sodium acetate make acetic acid and salt. it cant do both doesnt it?

It does both, the ions sodium, chloride, acetate and hydrogen is mixed in water and there is no way to tell which ion belongs to which.

Just like forming nitric acid when we add hydrochloric acid to a solution with nitrate salts.

Göran

thank you, im not chemist it is obvious. and i have a hard time getting used to the fact than mixing two salt together in a solvent only make something new when you remove them from the solvent

Göran is right of course, but further weak acids and bases are in an equilibrium state, not all of the acetic acid for example is in a protolyzed state, but it is in an equilibrium:
CH₃COOH + H₂O <=> CH₃COO^- + H₃O⁺
Also strong acids and bases are in an equilibrium, but it is in the case of (at least diluted) HCl completely on the right side:
HCl + H₂O => Cl^- + H₃O⁺

Now, a new chemical reaction can disturb this equilibrium by removing some of the ions, for example:
Cl^- + H₃O⁺ + AgNO₃ <=> HNO3 (actually as a strong acid also completely protolyzed) + AgCl(solid)
At this arrow to both sides you see it is also an equilibrium, but due to AgCl's very low solubility this reaction is almost completely to the right (quatitative precipitation). That is is still an equilibrium you can prove by reducing the AgCl by adding a reactive basemetal (typically Fe, Zn or Cu) in an acidic environment (typically H2SO4 or HCl - for instructions new members should search for [convert][silver][chloride] since not all combinations would work as well as others). If AgCl were not soluble at all, it would not react at all at those temperatures. But as we all know, it does - thanks to equilibrium reactions.

Hope this helps to get a feeling for, what happens.

Björn i right of course, and he shows a deeper understanding of the physical chemistry going on. Chemistry isn't only simple reaction formulas and to get to the next level you need to understand chemical equilibrium. Any reaction can go both ways, temperature and chemical concentrations decides where the equilibrium resides and toward which side of an equation the reaction goes.

There is a slight error in this statement

Also strong acids and bases are in an equilibrium, but it is in the case of (at least diluted) HCl completely on the right side:
HCl + H₂O => Cl^- + H₃O⁺

since even this reaction is in balance. A proof of this is the fact that hydrochloric acid have a smell, it is HCl going off as a gas. When the HCl is removed from the left side of the equation, more Cl^- + H₃O⁺ will combine into HCl to keep the reaction in equilibrium.
Another equilibrium is the pressure of HCl above the surface of the liquid. Until the partial pressure of HCl is high enough in the atmosphere above the surface there will be more HCl leaving the surface than dissolving into the liquid, but when the partial pressures is high enough there will be a molecule going back into solution from the gas for each molecule HCl that is leaving the liquid.... and we will have equilibrium.
The same process is affecting the water molecules.

In an open container we would see this as evaporation, while in a closed jug of acid we would get a slightly higher pressure than the surrounding atmosphere. A more common example is an opened bottle of cola, every time you opens the bottle you release the over pressure and the partial pressure of the carbon dioxide above the liquid goes down, releasing more from the liquid. If you put the cork back the pressure goes up again until the pressures are in equilibrium with the gases dissolved in the liquid.

I found a good link on hydrochloric acid when doing some research for this posting that I would like to share. It contains partial pressures of HCl and H₂O at different temperatures but also a lot other stuff about HCl.
http://www.jsia.gr.jp/data/handling_02e.pdf

This is fun stuff! 8)

Göran

 

[solar_plasma]

I tend to underestimate the physical properties of the environment (I always felt physical chemistry being too boring and to complicated :lol: ), of course what I said is a) only true under defined physical properties and b) always a simplificated model.

 

[g_axelsson]

Hey, don't stop now. We haven't even reached the field of quantum chemistry. :mrgreen:

Göran