Vinod950
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Making manganese nitrate ?
Hi, I am pretty lacking in chemistry knowledge so I was hoping one of you guys could help me.
I have been trying to make manganese nitrate as shown in nurdrage's video, and despite using reagent grade manganese dioxide from a science supply
store, i could not produce the clear manganese nitrate the video showed, mine always comes out orange. I was tryin to make it again, and this part is
probably gojng to be laughed at, but since i was out of distilled water, i thought id heat up hydrogen peroxide till it decomposes and i have pure
water, which id mic with mno2 and when fizzing stops, add nitric acid as per nurd rage's video. Well i didnt decompose the h202, so i added thr mno2
and was left with a black solution after some fizzing. I realized my dumb move and so dumped a bunch more h202 into 5g of mno2, about 50ml. Then adeed
10 drops of rfna to it, and after ten mins, was left with a clear solution with a slight pink tinge with a layer of very fine crystals at the
bottom???! I was in disbelief that this could be nitrate so i scooped some solution up and heated, and at first it just dried, then releassed orange
smoke and turnd silvery black just like mno2. But that cant be mno2 right? I didnt use oxalic acid at all? What happened?
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bfesser
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Thread Moved
8-9-2013 at 05:52 |
bfesser
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Among the many reasons I'm not going to answer your questions:
Not capitalizing element symbols properly. There's no such element as "h".
Writing "h202". Oxygen's symbol is the letter O, not a zero.
Undefined acronyms "rfna"—yes, I know what it means, but do you?
"As shown in nurdrage's video." Find a real reference.
Single paragraph post, which should clearly be three or more paragraphs if written to be readable.
Put more effort into your posts if you want genuinely helpful responses. Why should anyone else waste their effort if you can't be arsed to expend
your own?
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eidolonicaurum
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If you follow nurdrages video exactly, you will get manganese nitrate. His methods almost always work when repeated closely. However, you can almost
certainly get away with using tap water instead of distilled. I used nothing but tap water when I started out in chemistry. A good source of
'distilled wated' is the ice you get when you defrost the freezer. It cheap an pure enough for most purposes. The only times when it isnt good enough
are for very VERY sensitive reactions.
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phlogiston
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MnO<sub>2</sub> is a well known catalyst for decomposing H<sub>2</sub>O<sub>2</sub> into water and oxygen. So,
your H<sub>2</sub>O<sub>2</sub> decomposed when you added the MnO<sub>2</sub>, releasing oxygen gas (the fizzing),
and leaving MnO<sub>2</sub> particles suspended in water (the black "solution").
Then you added the nitric acid, dissolving the MnO<sub>2</sub> to yield a clear solution of manganese nitrate (and perhaps some excess
nitric acid). The pinkish crystals are indeed manganese nitrate.
When you heated a sample of the solution, it evaporated and then the mangese nitrate decomposed, as many nitrates do. The orange fumes were nitrogen
dioxide and the black/brown residue is indeed MnO<sub>2</sub> again.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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bfesser
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The original post was made four months ago. Quote: Originally posted by eidolonicaurum  | | A good source of 'distilled wated' is the ice you get when you defrost the freezer. It cheap an pure enough for most purposes. The only times when it
isnt good enough are for very VERY sensitive reactions. |
This is simply untrue.
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blogfast25
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Hmmm... I think it's part true. It certainly contains less salts than tap water. It's been distilled in a sense, so it's purer than most tap or
natural waters.
[Edited on 3-1-2014 by blogfast25]
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bfesser
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While I'm sure that it can be used for most things and it's purer than tap water, it's wrong to call it distilled water. What you just wrote also is
untrue; you can't just assert that it's "purer than most tap or natural waters." Please don't post unsubstantiated garbage.
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eidolonicaurum
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I never called it tap water. And where I live its much better than tap water. How do you obtain distilled water in sufficient quantity to do all the
experiments you undoubtably do?
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Mailinmypocket
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The pharmacy? I wait until it goes on sale and usually buy 4 litre bottles of steam distilled generic brand water for .99$. It is sold in an area
where they keep regular spring water and other drinks. Automotive stores sometimes have jugs of it also, for radiators albeit a bit pricier, it comes
in jugs identical to windshield washer. Unless where you live have nowhere that sells distilled water it is simply not very economical to distill your
own water vs. buying it if it can be had cheaply. I certainly wouldn't waste electricity or gas if I could spend a dollar and get four litres!
When I first started in chemistry I used tap water all the time, being naive. This quickly stopped when I realized that it caused problems, an example
being the preparation of silver nitrate solutions that went cloudy due to chlorides etc in the tap water. Now it's always distilled anytime a
preparation calls for water. Plus, it's nice to have the purest reagents possible right?
[Edited on 4-1-2014 by Mailinmypocket]
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blogfast25
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| Quote: Originally posted by bfesser | | While I'm sure that it can be used for most things and it's purer than tap water, it's wrong to call it distilled water. What you just wrote also is
untrue; you can't just assert that it's "purer than most tap or natural waters." Please don't post unsubstantiated garbage. |
Dear G-d, got out of bed with the wrong leg first?
You can't see the contradiction in your own writing? "While I'm sure that it can be used for most things and it's purer than tap water,
[...]"
I added the qualifier 'most'. Meaning 'not all'. Water that's been obtained by condensing air moisture is indeed likely to contain less
solids or salts than most tap water or well water. This may not always be the case for every single comparison but broadly speaking it's true.
I did not called it distilled water.
If you're going to be facetious, try at least to be right.
[Edited on 4-1-2014 by blogfast25]
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bfesser
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blogfast25, I am not being facetious; I am right.
First of all, "most" is the wrong qualifier, particularly when you're purely speculating. As I said, don't post unsubstantiated garbage. This is where you called it distilled water. That's like saying that a
cat is a dog, <em>in a sense</em>. If you mean sublimated, then write sublimated.
Also, you've now changed from "most tap or natural waters" to "most tap water or well water." While (I think) that the latter is more likely to be
true, it's still mere speculation, which you shouldn't be presenting as fact—something you're in the habit of doing.
Finally, while I'm sure that the condensed ice is quite pure H<sub>2</sub>O, that purity is likely diminished or lost altogether in the
process of collecting it and converting it back to a liquid. As I see it, there are two ways of recovering the frost; scraping it out, or letting it
thaw and collecting from the drip pan. The first is likely to chip off bits of paint and other crap which will contaminate the water. The second is
going to collect contaminants from the inside surfaces of the freezer and drip pan. As I said, it's <em>likely</em> better than the tap
water in his area, but it's not a certainy, it surely depends on the source of tap water and his (presumed male) recovery technique.
<img src="../scipics/_warn.png" /> <em>Now, as a moderator, I'm going to tell you two things.</em> First, please stop presenting
speculation as fact. Second, stop with the arrogant responses when someone corrects you—particularly the <em>ad hominem</em>
replies ("Dear G-d, got out of bed with the wrong leg first? . . . If you're going to be facetious, try at least to be right."). Reply with civility,
or silence. <img src="../scipics/_warn.png" />
<hr width="80%" />
eidolonicaurum, I'm fortunate to live in an area where fresh water is plentiful, clean, and cheap. We've also got abundant energy,
so distilled water is commercially available. The grocery stores in my area have it for 99¢ USD per gallon (~4 L).
On an unrelated note, does your name mean something along the lines of 'image in gold'? Regardless, welcome to Science Madness! 
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blogfast25
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Keep parsing syllables, bfesser.
We'll have to agree to disagree.
That's my very last word on this extremely silly matter.
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eidolonicaurum
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| Quote: Originally posted by bfesser |
On an unrelated note, does your name mean something along the lines of 'image in gold'? Regardless, welcome to Science Madness! |
So close, yet so far. 
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woelen
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@bfesser: In this case I have to go with blogfast25. This quarrel about the 'distilled' water is silly and is nothing more than nitpicking on
irrelevant details. Let's please go back to the main subject of this thread.
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