mattrod9523
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Ammonium Chloride + Sodium Hydrogen Sulphate
I did an experiment with different chemicals to the ones I planned. Instead of heating a solid mixture of sodium bisulphate and sodium chloride, I
heated a mixture of sodium bisulphate and ammonium chloride. What gas/vapor is produced, and what does it become when entering water? Whatever was
produced, my litmus paper indicated an acid.
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Magpie
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2NH4Cl (s) + 2NaHSO4 (s) --->2 HCl (g) + (NH4)2SO4 (s) + Na2SO4(s)
That's my guess.
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Picric-A
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You will probably also get some breakdown of the NH4Cl as well...
After the experiment were the sides covered in a white powder?
Magpie- how did you come to the conclusion ammonium hydrogen sulphate was formed? My guess was the soloution was acidic becuase of the dissolved
NaHSO4 and the gas given off was HCl and NH3/HCl mix...
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chief
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In heat NH4X , with X=halogen, decomposes to NH3 + HX .
That's a equilibrium-reaction
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mattrod9523
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The thing that worries me is that ammonium chloride reacted differently with other chemicals. To form ammonia gas, ammonium sulphate must be heated
with calcium hydroxide. However, sodium carbonate and sodium hydroxide would have worked as well. They all have oxygen, odd numbers, too, if that
matters. The only way the ammonium chloride would have provided the nessecary elements for ammonia (NH3) would have been if only it released a
fraction of the NH in its formula. Seemingly... Or maybe the calcium hydroxide acted as some sort of barrier allowing only the NH3 of ammonium
chloride's NH4 to be released.
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Magpie
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| Quote: |
Magpie- how did you come to the conclusion ammonium hydrogen sulphate was formed?
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I didn't. Where do you see NH4HSO4 in my equation?
The poster implied that he mixed two powders then heated them. When HCl (a gas) is generated it escapes, removing itself from any equilibrium
considerations, and driving the reaction forward.
I believe NaHSO4 is acidic in nature as HSO4- is capable of releasing H+. This provides the driving force to form the HCl which, when absorbed in a
separate quantity of water, will turn litmus red.
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Picric-A
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Sorry i meant (NH4)2SO4.
He did heat them yes. But the two gasses NH3 and HCl recombine on the side of the upper part of the Beaker/test tube ect.. or in the air above it.,..
It is difficult to seperate the two gasses without them recombining.
As for you litmus red theory i agree.
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Magpie
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It's probably more complicated than my simple equation. For one thing he may have water of hydration with the NaHSO4.
Mattrod didn't mention any white product forming above the reaction mix. Since the mixture is acidic I assumed that NH3 was not produced.
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mattrod9523
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I did see a white residue left behind from the test tube with the ammonium chloride and sodium hydrogen sulphate powder mixture.
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mattrod9523
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However, when the two gases recombine, they form NH4Cl, which is ammonium chloride. So, maybe the gas was ammonium chloride gas. Still, the fact that
ammonium chloride solution is not acidic, means that the ammonia, serving as a strong base, neutralized the acidic properties of HCl, eliminates the
theory that if NH4Cl was broken up, it would release the two gases that make it up, and then recombine them. The solution was acidic, which means that
there was a presence of HCl in the solution. Most likely, anyway...
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mattrod9523
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What we need to know is what ammonium chloride emits when heated. Then, same with sodium hydrogen sulphate.
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mattrod9523
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I have just reasured that ammonium chloride (NH4Cl) breaks down into hydrogen chloride (HCl) and ammonia (NH3). Sodium hydrogen sulphate (NaHSO4) is
heated first to release water vapor, further to produce sodium disulphate (Na2S2O7) along with the release of water, and then the sodium disulphate
breaks down onto sodium sulphate Na2SO4) and sulfur trioxide (SO3). The thing that confuses me is what is made when the gas (s) enters water. I know
H2O + H2O = H2O. Next, the sodium disulphate is in gas state, but I don't know what it made when it entered water. I don't know if it broke down
before either. If it did break down before, it would have been sodium sulphate, sulfur trioxide and water. The sulfur trioxide would combine with
water to form sulfuric acid. The sodium sulphate, I don't know if it was in gas, liquid, or solid state.
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mattrod9523
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I did an experiment by heating sodium hydrogen sulfate in a test tube, closing the container with a holed stopper, inserting an angled rod, and having
the other end of it submerged in water. The problem was that when the salt was being heated, and the rod was submerged in water, the water was sucked
up through the rod and into the heating salt. This created a very strong acid, turning the litmus paper an extreme red. So I did it again today except
with the angled rod half a centimeter from the water. The solution was not half as acidic. HELP!!!!
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kclo4
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Hmm you seem like a pretty confused little guy, I'll attempt to explain whats going on.. but I'm no teacher by any means.
First off! no sodium compounds are going to be in a gas state. Look at the wikipedia, MSDS, etc. You'll see what I mean!
Its not called Sodium Disulfate, its called Sodium Pyrosulfate unless that is it synonym name. I have never heard of it.
Are you sure you aren't using Hydrated sodium bisulfate? You need to make sure that it is anhydrous before you do a test like you did.
This IS what is happening:
Upon Heating your mixture, it will first let off Hydrogen Chloride gas, after that reaction is done, you have a mixture of Ammonium and Sodium
Sulfate. No Chloride.
2 NH4Cl + 2 NaHSO4 = Na2SO4 + (NH4)2SO4 + 2 HCl
Since Ammonium Chloride Sublimates easily, you will likely lose a lot of your reactant.
Further heating of the mixture, now only containing Ammonium Sulfate and Sodium Sulfate leads to Ammonia gas, and also Ammonium Bisulfate.
(NH4)2SO4 = NH4HSO4 + NH3
The Ammonium Bisulfate will sublimate in a similar mechanism as Ammonium chloride does If the temperature is high enough. I highly doubt it could be
dehydrated to form Ammonium Pyrosulfate (NH4)2S2O7.
Although it is NOT technically like this, I think you would be able to understand what is going on if you look at Sodium Bisulfate as Na2SO4*H2SO4.
H2SO4 + 2 NH4Cl = (NH4)2SO4 + 2 HCl.
That is the basic reaction that is going on with your two reactants.
You probably want to get a good chemistry book to help you. Chemistry made simple was the first chemistry book I read and I believe It would help you
out. there are better ones out there however.
Also, you may be interested in reading about reactivity series, Polyprotic acids, why certain chemicals have different melting, boiling/sublimation
and decomposition points. etc.
Keep on learning! 
[Edited on 21-10-2008 by kclo4]
[Edited on 21-10-2008 by kclo4]
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mattrod9523
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Thank you. So the hydrogen chloride entered the water to form hydrogen chloride. Then, after the series of chemical changes, ammonia gas was produced.
So basically it was ammonia + hydrochloric acid. This makes ammonium chloride (NH4Cl). Am I right? If it did, would it be called ammonium chloride
solution or what?
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kclo4
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Well, you could collect the HCl in one solution, and collect the NH3 in another if you did it correctly.
If you continued to heat it and dissolved both gases that were produced in the same solution, then yes you'd have an ammonium chloride solution. If
you continued to heat it even more, the Ammonium Bisulfate would go over as well leaving behind Sodium Sulfate.
Keep in mind Ammonium chloride is also fairly acidic when it comes to chlorides.
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mattrod9523
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Thanks a lot. OK, end of thread.
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