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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: yoyoils on December 23, 2012, 04:16:35 PM

Title: Chlorine(g) ? using concentrated H2SO4
Post by: yoyoils on December 23, 2012, 04:16:35 PM
Since I've run out of my 32% HCl, and I want to make some Chlorine gas in a new experiment, but only have the following reagents that I think I could use:

Concentrated 98% H2SO4 & house hold Clorox Bleach.
MSDS:
http://www.thecloroxcompany.com/downloads/msds/bleach/cloroxregularbleach0809_.pdf


If someone would help me, i just want to be sure im not going to make ANYTHING gaseous but chlorine from mixing sulfuric acid with bleach.

I've read some places that u make H2SO4 + NaOCl -> Na2SO4 + HCl + SO2.. is this true? here's the source:
http://wiki.answers.com/Q/What_if_Sulfuric_acid_and_sodium_hypochlorite_are_mixed

^ It seems like they're just guessing and warning.

Because on the other hand, here's a source that says the opposite:
http://www.ehow.com/about_6521382_sulfuric-acid-chlorine-bleach-reaction.html

Basically says what I want to know, is that sulfuric acid + bleach will produce chlorine gas!!! please someone who knows help me big time
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: yoyoils on December 23, 2012, 04:33:45 PM
And plus this guy says: http://www.sciencemadness.org/talk/viewthread.php?tid=6590#pid75319 that you can make chlorine(I) oxide, which i definitely need only chlorine gas. please someone shine some light on here
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: Arkcon on December 23, 2012, 05:23:47 PM
If you need a small amount of gaseous chlorine, and you have conc. sulfuric, you can use household NaCl, which you should be able to get easily.
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: yoyoils on December 23, 2012, 06:22:34 PM
How much chlorine would that produce? I did it earlier to try and make some HCl acid, but the result was so diluted it was a waste of time

I always thought that would just make hydrogen chloride.

I've always made pretty good chlorine gas using 32%HCl + Household Bleach, but do you know if a certain prepared concentration of H2SO4 (w/w?%) may react properly with the bleach to form chlorine gas and nothing else crazy?
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: Arkcon on December 23, 2012, 06:57:32 PM
Whoops.  No. You're right, that just gives HCl.  I got confused as to what you were trying to make, even as I was typing it.
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: yoyoils on December 23, 2012, 08:21:14 PM
Why are wiki.answers and ehow both saying different things about mixing H2SO4 with bleach lol and are either of them right?
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: Borek on December 24, 2012, 04:00:01 AM
Why are wiki.answers and ehow both saying different things

Why are you surprised by the fact two random sources answering a random question give random answers?
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: Arkcon on December 24, 2012, 07:00:54 AM
As Borek: has alluded to, the chemistry of household bleach is complex.   Basically, it all depends on the final concentration of the acid and the hypochlorite, whether you will get mostly Cl2 and a small amount of other gaseous breakdown products, or other results.  I don't recall, off hand, the easy method for laboratory Cl2 generation (does wikipedia give a simple method like that, sometimes it does.)  Fact is, Yahoo answers, eHow, and wiki.answers ask and answer questions out of context, someone answering there may just be posting a random factoid, or may have a different application that won't be affected by impurities.  Or they have an efficient scrubber, again, for their application.
Title: Re: Chlorine(g) ? using concentrated H2SO4
Post by: ajkoer on May 01, 2013, 05:35:03 PM
Note per the ionic equations:

ClO(-) + Cl(-) + 2H(+) <=> Cl2 + H2O

there are many paths to generating chlorine. For example, for ClO(-), one can use NaOCl, Ca(OCl)2, HOCl,.

For the chloride, Cl(-), use HCl or NaCl. 

For H(+), usually a strong acid or acid salt like NaHSO4. Note, in the case of a too weak acid, only Hypochlorous acid is formed:

NaOCl + H2CO3 --> NaHCO3 + HOCl

However, there are interesting instances to have an acidic 'activity level' equivalent to a strong acid without, of course, the strong acid. For example, employing a highly concentrated ionic slurry (or acid salt hydrate) may work. Examples include MgSO4 (outlined in several patents to produce dibasic Magnesium hypochlorite, where Cl2 is formed as a byproduct) and even FeSO4 (discussed in an old sciencemadness thread where a syrup-like FeSO4/NaOCl mixture is reported to work best).

So understanding the mechanics of the reaction, one can generate Cl2 in a convenient manner.