[rctrackstar2007]

wait, if HCl is a strong acid then why does it not dissociate 100%? 

It does dissociate 100%.

then what is with the 35% business?

[mike]

It does dissociate.

It is a strong acid.

I think it just dissociates "better" in water than in toluene (from what the original posters says).

[Will]

what is with the 35% business?

Water can't hold that much HCl in it, so if you try and bubble more HCl into 36% hydrochloric acid then it won't dissolve. Only once the water dissolves the HCl, can it dissociate.

[rctrackstar2007]

I think it just dissociates "better" in water than in toluene (from what the original posters says).

OOOHHHH!! i get it now lol i forgot about the toluene factor of the convo. my bad

[mike]

35% is concentration.

[rctrackstar2007]

what is with the 35% business?

Water can't hold that much HCl in it, so if you try and bubble more HCl into 36% hydrochloric acid then it won't dissolve. Only once the water dissolves the HCl, can it dissociate.

ok that makes much more sense now

[mrdeadman]

It does dissociate.
It is a strong acid.

also, because it dissociates 100% (more or less) then there is no equilibrium.

producing H₂ gas

and it does not produce H₂ gas. if you smell really concentrated HCl, it reeks, it kind of feels like when you inhale concentrated ammonia gas.

[mike]

if you smell really concentrated HCl, it reeks, it kind of feels like when you inhale concentrated ammonia gas

Neither of which you should ever do.

[rctrackstar2007]

if you smell really concentrated HCl, it reeks, it kind of feels like when you inhale concentrated ammonia gas

Neither of which you should ever do.

i learned those the hard way plus N2O5 (common polution) i believe it was i made and got some of that out of the fume hood which was pretty nasty

[mrdeadman]

Neither of which you should ever do.

the gas effuses pretty fast, it's not like im deeply inhaling it. 

[mrdeadman]

i learned those the hard way plus N2O5 (common polution) i believe it was i made and got some of that out of the fume hood which was pretty nasty

hoods have vent fans for a reason. 

[Will]

because it dissociates 100% (more or less) then there is no equilibrium.

lol this is going round in circles. There is definately an equilibrium, even if the HCl has completely dissociated.

i learned those the hard way plus N2O5 (common polution) i believe it was i made and got some of that out of the fume hood which was pretty nasty

Was that nitric acid and P₄O₁₀? I'm no expert but I would guess N₂O₅ isn't a common pollutant.

[mike]

Safety first guys ;-)

[mrdeadman]

lol this is going round in circles. There is definately an equilibrium, even if the HCl has completely dissociated.

why is there an equilibrium if it is 100% dissociated, might i ask?

[Will]

why is there an equilibrium if it is 100% dissociated, might i ask?

it must be an equilibrium, because if you removed the water, then the H₃O⁺ and Cl^- would form H₂O + HCl  to replace the lost water (Le Chatelier's principle).
But it would be cool if that did happen, then you could evaporate off the excess water and be left with hydronium chloride (hydrochloric acid has too low an ionization constant (10⁷) for that to be possible).

but it's not an equilibrium reaction  Le Chatelier's principle will only qualify if it is one. in this case when you take out the water there will just be excess HCl...

Wait a sec, I thought you just said there isn't any HCl because its all gone to H₃O⁺ and Cl^- and theres no way its going back!

Edit: Also, why do I see my conc. hydrochloric acid fuming!!?? lol

In one sentence: If it can go the other way, ie. if I can get HCl gas out of hydrochloric acid, then it is an equilibrium.