[candiishop]

Why bonds in gaseous HCl are covalent? Since HCl in toluene gives a conductivity of zero and HCl in water is 100.

[Bakegaku]

When dissolved in water, HCl is in equilibrium with dissociated ions due to the molecular forces of water.

H₂O + HCl (aq) <-> H₃O⁺ + Cl^-

Toluene does not react with HCl in this way, and so very few ions are formed to conduct.

There isn't actually a strictly distinguished difference between ionic and covalent bonds.  The hydrogen in HCl has enough control over its electron to be considered covalent, but if they were to split it's probable that the Chlorine would strip the Hydrogen of its electron. 

[mrdeadman]

When dissolved in water, HCl is in equilibrium with dissociated ions due to the molecular forces of water.

H₂O + HCl (aq) <-> H₃O⁺ + Cl^-

Toluene does not react with HCl in this way, and so very few ions are formed to conduct.

There isn't actually a strictly distinguished difference between ionic and covalent bonds.  The hydrogen in HCl has enough control over its electron to be considered covalent, but if they were to split it's probable that the Chlorine would strip the Hydrogen of its electron. 

Hold on there buddy, HCl is a strong acid so there is no equilibrium.

[Will]

When dissolved in water, HCl is in equilibrium with dissociated ions due to the molecular forces of water.

H₂O + HCl (aq) <-> H₃O⁺ + Cl^-

Toluene does not react with HCl in this way, and so very few ions are formed to conduct.

There isn't actually a strictly distinguished difference between ionic and covalent bonds.  The hydrogen in HCl has enough control over its electron to be considered covalent, but if they were to split it's probable that the Chlorine would strip the Hydrogen of its electron. 

Hold on there buddy, HCl is a strong acid so there is no equilibrium.

Hold on there buddy, 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).

[rctrackstar2007]

When dissolved in water, HCl is in equilibrium with dissociated ions due to the molecular forces of water.

H₂O + HCl (aq) <-> H₃O⁺ + Cl^-

Toluene does not react with HCl in this way, and so very few ions are formed to conduct.

There isn't actually a strictly distinguished difference between ionic and covalent bonds.  The hydrogen in HCl has enough control over its electron to be considered covalent, but if they were to split it's probable that the Chlorine would strip the Hydrogen of its electron. 

Hold on there buddy, HCl is a strong acid so there is no equilibrium.

true, it'll dissociate 100% so it won't go back to HCl

and Cl is a non-metal, metals are the ones that form ionic bonds, so a non-metal won't form an ionic bond but rather a covalent one

[rctrackstar2007]

Hold on there buddy, 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...

[Will]

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

[rctrackstar2007]

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

ah true, but because this is true then there will be no water to take out

[rctrackstar2007]

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

producing H₂ gas

[mike]

I don't understand the last couple of posts

Concentrated HCl is still only about 35% or so.

I doubt "fuming" HCl produces hydrogen gas it sure smells like HCl to me

[rctrackstar2007]

35% what? dissociation?

[mike]

35% HCl

[Will]

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!

ah true, but because this is true then there will be no water to take out

I don't think you can get anywhere over 40% conc. hydrochloric acid (mine is 36%) therefore there must be at least one water molecule to take out! There is a certain concentration, whereby if you take out more H₂O instead of getting more concentrated, HCl gas is given off.

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

producing H₂ gas

lol, I hope not, otherwise the cheap plasticy cap would come flying off from the pressure of the H₂ and I would regret keeping the HCl in my room as my mom would gloat about how she was right that I should keep it in the basement, not 2 metres away from where I work and sleep!

35% what? dissociation?

35Kg HCl 'molecules' (which are dissociated) per 100Kg hydrochloric acid

[rctrackstar2007]

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

and because i am confused about this leads to my incorrect statements in the other posts 

[Will]

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

It does dissociate 100%.