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Chlorine


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Electrolysis of brine (salt water) would produce it, you could place a test tube (or other container) over the electrode and then once it's gathered in their place a stopper (or 'lid') over the test tube (or other container) to make the the Cl2 doesn't escape.

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There are literally dozens of threads here at the forums going over how to generate, clean, dry, and contain chlorine gas. PLEASE use the search engine and you will find more than you'd ever hope to learn about chlorine gas creation. :D

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":edit: I'm not gonna kill anyone :edit:"

it's ok; we know it's very, very hard to die as a result of exposure to chlorine gas.

 

but really, search around.

 

 

 

just a side note: after going through today's new posts, i think we REALLY need to divide the chem forums into subforums or something. waaay too many posts for one forum.

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Electrolysis of brine (salt water) would produce it, you could place a test tube (or other container) over the electrode and then once it's gathered in their place a stopper (or 'lid') over the test tube (or other container) to make the the Cl2 doesn't escape.

 

 

How could this possibly work for good, clean Cl2??? You wouyld also get the production of O2 at the electrode (or maybe H2, but i think its O2)

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Here you have a picture I made of how I make chlorine gas. Very easy to make. Text is in dutch, but i think it can't be that difficult to translate. When you've made it you should hold a copperwire in the erlenmeyer with chlorine gas. Very nice experiment. When the reaction stops, just place the wire in a bunsen flame a you will have a nice blue color.

Opstelling Synthese Dichloor in Kleur met Tekst.bmp

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Chlorine smells exactly like bleach and like a pool because both household bleach and a well sanitized pool emit chlorine gas. (Due to the equillibrium of Cl2 + 2NaOH <=> NaClO + NaCl + H2O. ) So when you open a bottle of bleach, you are smelling a minute trace of chlorine gas. When you stand next to a pool that was just recently chlorinated, you are smelling a trace amount of chlorine gas.

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Chlorine smells exactly like bleach and like a pool because both household bleach and a well sanitized pool emit chlorine gas. (Due to the equillibrium of Cl2 + 2NaOH <=> NaClO + NaCl + H2O. ) So when you open a bottle of bleach, you are smelling a minute trace of chlorine gas. When you stand next to a pool that was just recently chlorinated, you are smelling a trace amount of chlorine gas.

No, I don't think so. What you are smelling is not Cl2, but very dilute HOCl.

Hypochlorite is a very weak acid and especially in swimming pools, where water pH is kept near neutral for obvious reasons, quite some HOCl is formed:

 

ClO(-) + H2O <--> OH(-) + HOCl.

 

Chlorine really has a different smell. Just add a few drops of bleach to dilute HCl and sniff the mix carefully. Really, it is quite different.

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I beg to differ. The only way you can 'smell' something is if it is airborne and has volatalized. HOCl just simply will not be volatalized in order for you to smell it. HOCl and NaOCl are virtually the exact same thing. When in solution, an equillibrium exists resulting in the production of minor amounts of chlorine gas. The smell from a bottle of bleach is the smell of chlorine gas. There is no doubt about that. Hypochlorus acid is not a stable acid.

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I beg to differ. The only way you can 'smell' something is if it is airborne and has volatalized. HOCl just simply will not be volatalized in order for you to smell it. HOCl and NaOCl are virtually the exact same thing. When in solution, an equillibrium exists resulting in the production of minor amounts of chlorine gas. The smell from a bottle of bleach is the smell of chlorine gas. There is no doubt about that. Hypochlorus acid is not a stable acid.

 

I would say, try it (but be careful). There really is a difference!

 

According to the book "chemistry of the Elements" by Greenwood and Earnshaw, HOCl is volatile and exists in the gas phase. Its solutions can be concentrated to up to 5 mol/l, but in that concentration, quite some HOCl exists in the form of Cl2O (Cl2O + H2O <--> 2HOCl, at zero degrees the equilibrium constant K = 3.5*10^(-3) mol/l). Its solutions really do volatilize and so they can be smelled.

 

I agree with you that HOCl is unstable, but not to the extent as you suggest.

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How could this possibly work for good, clean Cl2??? You wouyld also get the production of O2 at the electrode (or maybe H2, but i think its O2)

 

Its H2 at the anode but you can easily remedy this by separating the electrodes enough and placing a container directly above (or have the cathode penetrate the bottle) the cathode and collect the chlorine gas. ( the chlorine comes from the NaCl of the salt solution and the negatively charged Cl ion is attracted to the positively charged cathode where it combines with another Cl ion to form the stable Cl2). So, in effect you will get only pure Cl2 released above the cathode. Any other contaminates will be non-gaseous and therefore wont dillute your Cl collection. I think the hyrdrogen is released from the anode because of its strong electronegativity... This is my own personal understanding based on my own independent reading so please correct me if I am wrong on any of this.

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Its H2 at the anode but you can easily remedy this by separating the electrodes enough and placing a container directly above (or have the cathode penetrate the bottle) the cathode and collect the chlorine gas. ( the chlorine comes from the NaCl of the salt solution and the negatively charged Cl ion is attracted to the positively charged cathode where it combines with another Cl ion to form the stable Cl2). So, in effect you will get only pure Cl2 released above the cathode. Any other contaminates will be non-gaseous and therefore wont dillute your Cl collection. I think the hyrdrogen is released from the anode because of its strong electronegativity... This is my own personal understanding based on my own independent reading so please correct me if I am wrong on any of this.

I think you exchanged the role of anode and cathode. Cl2 is formed at the anode and H2 is formed at the cathode.

Another point is that you WILL get gaseous contaminants. At the anode you also will have formation of oxygen. Formation of chlorine gas and formation of oxygen are two competing reactions. The conditions must be carefully controlled in order to minimize the production of oxygen at the anode.

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