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j_sum1
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My hardware store hydrochloric acid seems to be contaminated with Ti (of all things).
It gives a pale purple / lilac cloudy hue when reacting with zinc or magnesium.
It forms a bright orange complex with a very small of dilute peroxide.
Or is there something else that would give this same set of results?
How would titanium contamination even happen?
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Morgan
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Decibel meters
Any thoughts on buying a decibel meter, what weaknesses or drawbacks come into play or best buy on eBay? There're some for 15 dollars or so supposedly
very accurate.
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Sulaiman
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Commercial decibel meters have (or did have in my time) selectable weighting curves and most importantly, they were calibrated.
Calibrated equipment allows 'legal' measurements (in my case noise levels in train cabins),
a cheap or diy sound level meter could be technically as good or even superior,
but it would not be acceptable for commercial monitoring purposes.
A sound level meter is a fairly simple device,
it is the calibration that is important.
CAUTION : Hobby Chemist, not Professional or even Amateur
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G-Coupled
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Quote: Originally posted by Morgan  | | Any thoughts on buying a decibel meter, what weaknesses or drawbacks come into play or best buy on eBay? There're some for 15 dollars or so supposedly
very accurate. |
If you've a half decent smartphone, look for any number of free apps which use your phone's
hardware to act as a decibel meter.
Some of them seem to work pretty well.
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Morgan
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Thanks for those thoughts all. I was reading some of the complexities of measuring sound on Wiki. This was interesting too.
"However, the reading from a sound level meter does not correlate well to human-perceived loudness, which is better measured by a loudness meter.
Specific loudness is a compressive nonlinearity and varies at certain levels and at certain frequencies.These metrics can also be calculated in a
number of different ways."
https://en.wikipedia.org/wiki/Sound_level_meter
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Sulaiman
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Accoustics and auditory perception is a complex area,
accoustics and especially sonar were the key topics of some of my lecturers and their post-grad researchers,
about 30 years ago I was designing, building and selling (small private sales) 'Hi-Fi' equipment,
one of the important areas is perceived loudness
https://en.wikipedia.org/wiki/Equal-loudness_contour
but the most complex is Psychoacoustics
https://en.wikipedia.org/wiki/Psychoacoustics
(I can discuss this topic ad nauseum)
What is the intended use for the sound level meter ?
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Morgan
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I wanted to know the level of sound some of my smallish jam jar jets make with exhaust tubes attached which increases the robustness enough so that I
wear hearing protection - just hot gases going in and out a single orifice somewhat fast.
This sort of thing as an example.
https://www.youtube.com/watch?v=T-EoSOfaplo
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j_sum1
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| Quote: Originally posted by j_sum1 | My hardware store hydrochloric acid seems to be contaminated with Ti (of all things).
It gives a pale purple / lilac cloudy hue when reacting with zinc or magnesium.
It forms a bright orange complex with a very small of dilute peroxide.
Or is there something else that would give this same set of results?
How would titanium contamination even happen? |
Bumping this since the exact same question with the same product has come up with another user. I think Ti is the most likely culprit: nothing else I
know fits the symptoms. But how would Ti have gotten in there? Seems a mystery.
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j_sum1
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sodium bichloride (say what?)
My latest project has been installing a small swimming pool. It is filling as I type. (Yay! Relief from the aussie heat!)
It comes with a couple of manuals that appear to have been kludged together from a range of models and passed through at least one poor translation
process. It is a bit unclear to say the least.
When it comes to the section(s) on chemicals to maintain correct water chemistry, there is a mountain of conflicting and contradictory information.
It mentions sodium dichloroisocyanuric acid. It also mentions bromine in one place. It has an ozone generator and so mentions that. It recommends
monopersulfate. But the bulk of the instruction centres around "sodium bichloride". I am wondering what on earth is meant by that.
Any insights? It is clearly an inappropriate name for something. But what? Does anyone know of any pool chemicals that are commonly misnamed as
sodium bichloride?
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woelen
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The only one I can think of is sodium hypochlorite. Where I live, we can buy big jugs (10 liters, or even 20 liters) of 12.5% active chlorine
(solution of NaOCl in water). This is poured in a swimming pool for chlorinating purposes. Sometimes it is combined with cyanuric acid in order to
stabilize the chlorine. This is important for outdoors swimming pools in full sunshine, which otherwise suffer from rapid decomposition of the
hypochlorite to chloride and oxygen by UV-light.
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karlos³
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Maybe they meant sodium bisulfate, which is a common pH-down pool chemical?
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wg48temp9
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| Quote: Originally posted by j_sum1 | My latest project has been installing a small swimming pool. It is filling as I type. (Yay! Relief from the aussie heat!)
It comes with a couple of manuals that appear to have been kludged together from a range of models and passed through at least one poor translation
process. It is a bit unclear to say the least.
When it comes to the section(s) on chemicals to maintain correct water chemistry, there is a mountain of conflicting and contradictory information.
It mentions sodium dichloroisocyanuric acid. It also mentions bromine in one place. It has an ozone generator and so mentions that. It recommends
monopersulfate. But the bulk of the instruction centres around "sodium bichloride". I am wondering what on earth is meant by that.
Any insights? It is clearly an inappropriate name for something. But what? Does anyone know of any pool chemicals that are commonly misnamed as
sodium bichloride? |
Perhaps if you gave more context by posting the relevant section of the instructions it may be obvious what chemical they are referring to.
If the instructions are unclear and conflicting why not ignore them. There is lots of info on the web about maintaining the chemistry of a swimming
pool. I would think if you are going to use the ozone generator you will have to pick a chemistry that's compatible with that.
I am wg48 but not on my usual pc hence the temp handle.
Thank goodness for Fleming and the fungi.
Old codger' lives matters, wear a mask and help save them.
Be aware of demagoguery, keep your frontal lobes fully engaged.
I don't know who invented mRNA vaccines but they should get a fancy medal and I hope they made a shed load of money from it.
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j_sum1
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Clearest statement anywhere in the manual:
| Quote: | | We recommend using chlorine particles of sodium bichloride for water disinfection, because sodium bichloride can be completely and rapidly dissolved
in water and its PH value is close to neutral. |
The most likely candidate would be Na-DCCA. Sodium salt with two chlorines so the name fits. Soluble solid with little affect on pH.
You are correct: I am not going to rely on the manual since it is so unclear. But it was important to read anyway. I do need to select a treatment
process compatible with materials used in the pool. I have read a few online guides as well. I am happy with the chemical theory. I am not happy
with some of the terminology and descriptions given. And I am trying to get my head around quantities. All the guides refer to "total alkalinity"
measured in ppm as separate from pH. I would much prefer molar concentration of carbonate if that is what is meant. I have read some truly shocking
descriptions of chemical equilibrium. Fortunately there is some good information amidst all the crap out there.
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arkoma
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The Mandarin to English translator strikes again
*edit* pulled some generic acetaminophen by refluxing the pills in acetone. The damn stuff xtallized this weird reddish color. Any thoughts?
[Edited on 1-9-2020 by arkoma]
"We believe the knowledge and cultural heritage of mankind should be accessible to all people around the world, regardless of their wealth, social
status, nationality, citizenship, etc" z-lib
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CharlieA
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Did you use pills that may have contained a red dye? Perhaps the dye was adsorbed on the crystals. You could try treating your acetone solution with
activated carbon to remove the dye before the crystallization step. Also, washing the crystals on the filter with acetone may remove the dye, assuming
that it is adsorbed onto the crystals of product.
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yobbo II
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Does anyone know where I can get a datasheet for a R450 photo multiplier tube.
TIA,
Yob
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Abromination
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Can sodium sulfate be used instead of potassium sulfate to precipitate neodymium and iron as a double sulfate salt?
Thanks
List of materials made by ScienceMadness.org users:
https://docs.google.com/spreadsheets/d/1nmJ8uq-h4IkXPxD5svnT...
--------------------------------
Elements Collected: H, Li, B, C, N, O, Mg, Al, Si, P, S, Fe, Ni, Cu, Zn, Ag, I, Au, Pb, Bi, Am
Last Acquired: B
Next: Na
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clearly_not_atara
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A lot of sources say that phenylacetic acids are especially prone to decarboxylation. However, I've had trouble finding any published reports
describing this decarboxylation under ordinary conditions. There are some papers about gas-phase decarboxylation, papers in supercritical
water, papers using UV-C photodecarboxylation, etc. I've heard the vinylogy explanation but experimentals, kinetics etc are hard to find since you
just get a bunch of recent papers using this or that catalyst for decarboxylative whatever.
In particular, the simple decarboxylation of naproxen to 2-methoxy-6-ethylnaphthalene is widely reported as an undesired side-reaction, but if you
search for references you get a bunch of catalytic oxidative decarboxylations which give the wrong product and are overcomplicated. I did find this:
https://pubs.acs.org/doi/10.1021/jp805614y
although at this point it might be faster to just CWE some Aleve and leave it out in the sun to see what happens
Abromination: this double salt is called "eldfellite", the data page describes it as "water-sensitive". i don't know a damn thing
about neodymium. however, sodium generally does not do as good a job as potassium when it comes to precipitating highly symmetric anions like ClO4-,
IO4-, or in this case Fe(SO4)2-. I don't know a damn thing about neodymium, unfortunately.
https://www.mindat.org/min-35791.html
[Edited on 29-3-2020 by clearly_not_atara]
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Tsjerk
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I found some 2,2-bipyridine! Some ideas to do some nice coordination chemistry with it?
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clearly_not_atara
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It forms lots of copper complexes, which are apparently good Ullmann reaction catalysts and can also catalyze the dehydrogenation of alcohols with
atmospheric oxygen.
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clearly_not_atara
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Does the Sandmeyer reaction work for alkyl fluorides with alkali nitrite and hydrofluoric acid? All I can find with Google are a bunch of sites
mentioning that it doesn't work well for aryl fluorides, but copper is not required for the alkyl Sandmeyer reaction, so that doesn't tell me very
much.
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Lion850
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I tried to process lead-tin solder into iodides. The lead went well, but the tin nearly all ended up as a very fine white powder which I assume is tin
(iv) oxide SnO2. This powder seems very unreactive. It did not dissolve in room temperature HCl. With very hot H2SO4 I got a charcoal coloured
substance which seems inert. Any suggestions how SnO2 can be processed into other tin salts?
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mackolol
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Hey, I have short question. Is it better (for glass or in general) to apply vacuum to distillation setup when it is fully heated, or to apply it at
the beginning and then heat along with vacuum?
[Edited on 20-4-2020 by mackolol]
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Sulaiman
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Apply vacuum first then heat,
if you heat first, when you apply vacuum there is a good chance of violent boiling.
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fusso
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| Quote: Originally posted by Sulaiman | Apply vacuum first then heat,
if you heat first, when you apply vacuum there is a good chance of violent boiling. |
You forgot that the heat
would also increase the pressure causing an explosion.
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