dawsonsuen
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ClO3- VS HSO4-
Just out of curiosity.
Since NaClO would react with an acid to form Cl2,
Would NaClO3 react with KHSO4 to form Cl2 and O2?
If not, would they simply swap ions to produce KClO3 and NaHSO4?
Also, what would happen if I mix a solution of NaCl and a solution of KHSO4?
Will I end up with KCl and NaHSO4?
PS: My aim is to produce some KClO3 out of NaClO3, NaCl, KHSO4.
Any good suggestions? 
Thank you very much.
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Praxichys
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You can make KClO3 from NaClO3 using only KCl. KClO3 is much less soluble than NaClO3. Just add some KCl to a NaClO3 solution and fractionally
crystallize.
NaClO3 reacts with acids (including KHSO4) to form chlorine dioxide, a green gas. This will explosively decompose into chlorine and oxygen. Be
careful!
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Bot0nist
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Many stores carry sodium free salt substitutes. This is KCl, with a little anti-cake added. It works well enough for metathesis praxichys suggests.
U.T.F.S.E. and learn the joys of autodidacticism!
Don't judge each day only by the harvest you reap, but also by the seeds you sow.
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dawsonsuen
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Thank you Praxichys and Bot0nist for your reply.
So it's not suggested to mix KHSO4 and NaCl to obtain KCl?
Or will they even swap ions to form KCl and NaHSO4?
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chornedsnorkack
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I am suspicious about that.
Cold aqueus HClO3 is said to be stable in concentrations up to 30 %, and to be strong, fully dissociated acid under these conditions.
This suggest to me that medium strength acids like HSO4- or H3PO4 should not be able to cause
HClO3 decay.
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woelen
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HClO3 indeed is quite stable when dilute. I have done experiments with boiling saturated solutions of KClO3 in 20% H2SO4 and these solutions were
stable, even when boiling.
Solid KClO3, to which conc. H2SO4 is added decomposes. You get a red liquid, which gives off intensely colored yellow gas. When a little organic stuff
(e.g. dust) comes in contact with the red liquid, you easily get an explosion.
I would expect a mix of NaClO3 and KHSO4 not to form any ClO2, as long as the material is kept cool and dry. On heating, or when it becomes humid, I
can imagine that some ClO2 is formed. A nice experiment may be to mix a spatula of powdered NaHSO4 and KClO3 and add a tiny amount of water and allow
the mix to stand. Maybe you get some yellow coloring.
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chornedsnorkack
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Quote: Originally posted by woelen  | HClO3 indeed is quite stable when dilute. I have done experiments with boiling saturated solutions of KClO3 in 20% H2SO4 and these solutions were
stable, even when boiling.
I would expect a mix of NaClO3 and KHSO4 not to form any ClO2, as long as the material is kept cool and dry. On heating, or when it becomes humid, I
can imagine that some ClO2 is formed. A nice experiment may be to mix a spatula of powdered NaHSO4 and KClO3 and add a tiny amount of water and allow
the mix to stand. Maybe you get some yellow coloring
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Whereas I´d expect solutions of NaHSO4 to be weaker acids than 20 % H2SO4.
| Quote: Originally posted by woelen |
Solid KClO3, to which conc. H2SO4 is added decomposes. You get a red liquid, which gives off intensely colored yellow gas. When a little organic stuff
(e.g. dust) comes in contact with the red liquid, you easily get an explosion.
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Pure ClO2 is described to be pretty soluble in water, but as a molecular solution, without hydrolysis in absence of strong bases. It also
is described to condense at +11 Celsius - although bulk liquid chlorine dioxide would be an energetic material.
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dawsonsuen
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I've just mixed a small sample of NaClO3 and KHSO4 together and there was an immediate evolution of a pale yellow gas and it also gave the solution a
yellow colour.
I suspect that this yellow gas was ClO2. (I'm not sure of a test for ClO2.)
My sample of NaClO3 was obtained by boiling a bleach solution at 110°C for 3 hours so the NaClO decomposes into NaCl and NaClO3. So there might still
be a small amount of NaClO left in the solution but I doubt that.
Surely the left over NaClO wouldn't react with the KHSO4 to form yellow ClO2 gas(?)
From what I know of, NaClO only react to form Cl2 gas.
Please reply if anyone has any thoughts about this.
Also, if anyone could come up with an equation between NaClO3 and KHSO4, please reply!
Thank you in advance!
[Edited on 13-8-2015 by dawsonsuen]
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chornedsnorkack
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| Quote: Originally posted by dawsonsuen | I've just mixed a small sample of NaClO3 and KHSO4 together and there was an immediate evolution of a pale yellow gas and it also gave the solution a
yellow colour.
I suspect that this yellow gas was ClO2. (I'm not sure of a test for ClO2.)
My sample of NaClO3 was obtained by boiling a bleach solution at 110°C for 3 hours so the NaClO decomposes into NaCl and NaClO3. So there might still
be a small amount of NaClO left in the solution but I doubt that.
Surely the left over NaClO wouldn't react with the KHSO4 to form yellow ClO2 gas(?)
From what I know of, NaClO only react to form Cl2 gas.
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Did you separate NaCl from NaClO3?
Also, Cl2O is also described as yellow.
How would you test a yellow gas suspected to be Cl2 or Cl2O or ClO2, or mixture of two of them or all three?
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woelen
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Interesting to read that NaHSO4 and NaClO3 give some ClO2. As I wrote, I could imagine formation of ClO2. The formation of ClO2 is not driven by the
strength of acid, but by the absence of sufficient water. HClO3 only is stable at concentrations less than 30%. So, if you have solid NaHSO4 and solid
NaClO3, then there is hardly any water (only some absorbed humidity).
The reaction is as follows:
NaHSO4 + NaClO3 --> Na2SO4 + HClO3
HClO3 in turn decomposes to give HClO4, ClO2 and water. I leave it as an exercise to write the balanced reaction equation.
I do not expect formation of Cl2O. Cl2O is much harder to make in visible amounts than ClO2 and requires quite specific conditions for its formation
in macroscopic quantities. If there still is some chloride as well in the chlorate, then you also get Cl2, besides the ClO2.
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chornedsnorkack
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| Quote: Originally posted by woelen |
HClO3 in turn decomposes to give HClO4, ClO2 and water. I leave it as an exercise to write the balanced reaction equation.
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Some balanced equations:
3NaClO3+2NaHSO4->NaClO4+2ClO2+2Na2SO4+H2O
2NaClO3+2NaCl+4NaHSO4->Cl2+2ClO2+4Na2SO4+2H2O
NaClO3+5NaCl+6NaHSO4->3Cl2+6Na2SO4+3H2O
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woelen
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Reactions 1 and 2 are the main reactions. The last one does not occur.
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