Wikipedia:Reference desk/Archives/Science/2017 March 18

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March 18

water hardness

This site[1] says the water hardness for Vancouver, WA is 60 to 160 ppm. Looking that up in Hard_water#Hard.2Fsoft_classification show that 60 ppm is soft, while 160 ppm is considered hard.

1. Is it normal for water hardness to vary over such a wide range?

2. What causes such variations? ECS LIVA Z (talk) 02:00, 18 March 2017 (UTC)

Note these are highest and lowest values recorded which would not necessarily correspond to "normal variation." It's common for hardness levels vary substantially, for example due to seasonal and interannual fluctuations of precipitation, source from which the water is drawn, etc. See e.g. [2]Shock Brigade Harvester Boris (talk) 02:11, 18 March 2017 (UTC)

This says the readings are from 60-130 - a little closer together, but not much. If you examine the other tests, you see even larger variations than the 100% for hardness. I initially assumed there were multiple sources, but this says they're all from aquifers. Of course, each aquifer may be slightly different and there are apparently 40 separate wells being tapped. As far as whether it's normal or not, the same kind of report on my local water supply is not broken down in quite the same way, but there are values that also more than double in scale. Matt Deres (talk) 02:42, 18 March 2017 (UTC)

The cause is minerals, usually Chalk in the water and each Water well has its own composition dependent on the surrounding Soil that contains the ground water which is filling it. --Kharon (talk) 03:34, 18 March 2017 (UTC)

The cause is the presence of soluble minerals, especially calcite in the aquifer rock itself (not really soil). In southern England for example Chalk Group aquifers deliver the typically hard water generally encountered there, although the sandstones of the Lower Greensand Group aquifers [3] deliver softer water. Mikenorton (talk) 12:12, 18 March 2017 (UTC)

Can electrical current change a chemical bond from covalent to ionic?

I swear this is not homework. I am not a chemistry student. I just want to have a little sharper understanding of atoms and not sure I understand this right:

Can a covelant bond between 2 nonmetals suddenly be changed into ionic bond somehow? — Preceding unsigned comment added by 79.178.144.67 (talk) 08:03, 18 March 2017 (UTC)

See ionization -- the short version is, a high enough electric current can break a covalent bond with the formation of 2 ions, but it wouldn't be an ionic bond because the ions wouldn't remain bonded to each other! 2601:646:8E01:7E0B:1812:83B6:C84E:722 (talk) 12:09, 18 March 2017 (UTC)

This is a tough one - I don't claim to know a good case. Obviously many ions will tend to react immediately - put H+ and OH- together and they turn into water again. An electric current is applied over a distance, so even if it coaxes the two apart, they will only find new partners in either direction. The best guess that I could think of in five minutes is ammonium hydroxide - in dilute aqueous solution, it is a combination of NH4+ and OH-; yet supposedly there is an "ammonium hydroxide gas" that seems most famously used in pink slime manufacturing, which if true should be an actual covalent molecule of NH4OH since ionic bonds don't tend to work in the gas state. That makes me wonder if you could come up with some nonpolar solvent where NH4OH stays covalent, but you could coax it apart for some duration with strong current. I have absolutely no idea if you can do this, but I've seen weirder chemistry. Wnt (talk) 23:19, 18 March 2017 (UTC)

"ionic bonds don't tend to work in the gas state" is a pretty broad claim. Sure, you lose the solvation that provides an alternative bonding to the ion-pairs, but that doesn't mean the alternative is that they actually share electrons rather than just electrostatically attract each other. Compare to doi:10.1063/1.3483897 and doi:10.1063/1.471520 as some lead refs determining NaCl and other classical ionic salts behave as ionic species in the gas phase. Even the nature of ammonia in water is not as clear-cut as "a combination of NH4+ and OH-". See for example doi:10.1364/JOSA.68.000429 that makes the case for more "NH₃ hydrogen-bonded to water" in contrast to other ammonium salts that actually have NH₄⁺ cations. DMacks (talk) 16:22, 19 March 2017 (UTC)

@DMacks: The first paper does indeed give the impression that gas phase NaCl has an entirely ionic character, with no covalent aspect to it at all. Thus their ring dimers, trimers and tetramers have mathematically polygonal angles - 90 or 120 or 135 degree angles. However... it's a simulation, and I wonder if that is truly accurate. Yet they clearly expect the opposite of what I did, and that would be a clue - thanks. But ... why aren't molecular orbitals even relevant here? Why don't they form some sp-like thing at all? And ... well, I was thinking that if covalent and ionic species could coexist in gas phase, you could excite one to the other, which would fulfill the OP's request. Wnt (talk) 13:21, 21 March 2017 (UTC)

A covalent network solid under an applied voltage can behave as a metal (e.g. graphite), as a semiconductor (e.g. diamond or silicon) or as a dielectric (e.g. silicon dioxide) -- depending on the band structure and, to a varying extent, on the presence of impurities (dopants). Applying electric current to a covalent network solid per se doesn't change the bond type. However, if the current is strong enough to cause a phase transition (by increasing the temperature and/or pressure) then all bets are off. Also, as mentioned above, a strong enough current will ionize some of the material, but that's not ionic bonding - just ions (plasma) Dr Dima (talk) 08:58, 19 March 2017 (UTC)

Instead of electricity, high pressure can do it, eg see. Also sodium under pressure can change from metallic bond to ionic and become an insulator. Nitrogen pentafluoride is predicted to be ionic under pressure, but would only exist as a mixture with covalent bonds at ambient conditions. Electric current flow in itself is unlikely to change bonds, as only very few bonds will be experiencing electron movement at anyone time. Perhaps a high magnetic field may make some kind of difference, but I don't know any examples. Graeme Bartlett (talk) 01:41, 20 March 2017 (UTC)

First fotoelement

returning troll/competence-hindered user. Collapsing. See WT:RD for explanation. --Jayron32 02:24, 19 March 2017 (UTC)
The following discussion has been closed. Please do not modify it.
Did a first fotoelement been electrotechnicaly (radiotechnicaly)?--79.139.157.152 (talk) 11:55, 18 March 2017 (UTC) Wikipedia has articles about Photoelectric effect, Photodetector and Evolution of the eye. Are these helpful? Blooteuth (talk) 13:26, 18 March 2017 (UTC) These are not so helpful. Did a photoelectric effect been explored at first in electrotechnic (radiotechnic)?--79.139.157.152 (talk) 15:01, 18 March 2017 (UTC) Take the time you need to read the articles, especially Photoelectric effect#History, and come back when you can express a question in the language they use. Blooteuth (talk) 15:42, 18 March 2017 (UTC) Thanks. Because electronic was started in the second part of XX century (in 1950 years), it gives me think that photoelectric effect been explored at first in electrotechnic (radiotechnic) which was started in the end of XIX century. These all gives me think that semiconductory effect did been explored at first in electrotechnic (radiotechnic). Is I’m right?--79.139.157.152 (talk) 16:35, 18 March 2017 (UTC) Did the first semiconductors been electrotechnicaly (radiotechnicaly)?--79.139.157.152 (talk) 17:14, 18 March 2017 (UTC) I recognise the Russian style here, and the strange confusion of tenses. Is this our old friend back? Dbfirs 18:27, 18 March 2017 (UTC) Is interesting, if the first transistors were electrotechnicaly (radiotechnicaly), how far the U.S. was ahead of the whole world?--79.139.157.152 (talk) 18:55, 18 March 2017 (UTC) "Did been"? Yes, this is highly typical of our site-banned friend. And there is no grammatical construction in actual Russian that would lead to this pseudo-construction. μηδείς (talk) 22:53, 18 March 2017 (UTC)

Organic chemist needed

I discovered Oxalate degrading enzyme in the speedy-deletion queues (someone had misidentified it as spam) a couple of days ago, since which time it's been significantly reworked — but not in fluent English, and the author clearly isn't familiar with our formatting or layout conventions. I've cleaned up the language and wikified it, but I'm not sure I've done the best. Here's how it looked ten minutes ago:

Extended content

Oxalate degrading enzymes Oxalate degrading enzyme, is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase. 1. Brief introduction 2. Classify 3. Calcium oxalate stones and oxalate degrading enzymes Brief introduction Enzymes are macromolecules with biocatalytic activity, and most enzymes are proteins. Almost all of the cellular processes in the body require enzyme involvement to improve efficiency. Oxalate degrading enzyme, is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase.[1] Classify Enzymes that currently degrade oxalic acid in the biology include oxalate oxidase, oxalate decarboxylase and formyl-CoA decarboxylase.[2] Oxalic acid oxidase（EC1.2.3.4）mainly in plants, it can degrade oxalic acid into carbon dioxide and hydrogen peroxide. Oxalate decarboxylase ( Oxalate decarboxylase，OXDC，EC4.1.1.2) is a kind of oxalate degrading enzyme containing Mn2+, mainly in fungi or some bacteria, it can be in the absence of other cofactors under the action of the degradation of oxalic acid directly to form formic acid and CO2.[1] Formyl-CoA decarboxylase（EC4.1.1.8）mainly mediated degradation of bacterial oxalic acid.[2] Calcium oxalate stones and oxalate degrading enzymes Calcium oxalate is the main component of urinary calculi, one of the important reason for leading to calcium oxalate stone disease is for the lack of degradation of oxalic acid metabolic pathway. Therefore, the use of oxalate degrading enzyme for degradation of oxalic acid in the human body has become an important research direction for the prevention and treatment of calcium oxalate stone disease.[2] Studies have shown that with the intake of a large number of foods rich in oxalic acid, the excretion urinary acid in the urine will be significantly increased. Therefore, to reduce the intake of exogenous oxalic acid can reduce urinary oxalate excretion, can significantly reduce the recurrence of stones.[3] Reference materials 1.  Properties and Application of Oxalate Decarboxylase Wikipedia [citation date 2016-12-14] 2.  Research progress of oxalate - degrading enzyme in the prevention and treatment of calcium oxalate. Wikipedia article [citation date 2016-12-14] 3. The Latest Development of Preventive Treatment of Calcium Oxalate Calculus. Wikipedia article [citation date 2016-12-14]

And here's what it looks like now:

Extended content

An oxalate degrading enzyme is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase. ==Brief introduction== Enzymes are macromolecules with biocatalytic activity, and most enzymes are proteins. Almost all of the cellular processes in the body require enzyme involvement to improve their efficiency. An oxalate degrading enzyme is a catalytic degradation of oxalic acid polymer protein, including oxalic acid oxidase, oxalic acid decarboxylase and formyl-CoA decarboxylase. ==Classification== Enzymes that currently degrade oxalic acid include oxalate oxidase, oxalate decarboxylase, and formyl-CoA decarboxylase. Oxalic acid oxidase（EC1.2.3.4）occurs mainly in plants. It can degrade oxalic acid into carbon dioxide and hydrogen peroxide. Oxalate decarboxylase (Oxalate decarboxylase，OXDC，EC4.1.1.2) is a kind of oxalate degrading enzyme containing Mn2+, mainly in fungi or some bacteria. It can appear in the absence of other cofactors under the action of the degradation of oxalic acid directly to form formic acid and CO2. Formyl-CoA decarboxylase（EC4.1.1.8）mainly mediates degradation of bacterial oxalic acid. ==Calcium oxalate stones and oxalate degrading enzymes== Calcium oxalate is the main component of urinary calculi. One of the important factors leading to calcium oxalate stone disease is the lack of degradation of the oxalic acid metabolic pathway. Therefore, the use of oxalate degrading enzyme to degrade oxalic acid in the human body has become an important research direction for the prevention and treatment of calcium oxalate stone disease. Studies have shown that with the intake of a large number of foods rich in oxalic acid, the excretion of urinary acid in the urine will be significantly increased. Therefore, reducing intake of exogenous oxalic acid can reduce urinary oxalate excretion, thus significantly reducing the recurrence of stones. ==References==

I've nowiki-ed all the section headers, since I don't want them messing with the WP:RDS table of contents or confusing the archiving bot.

Two questions: were all my changes improvements (or did I damage something unknowingly), and what else can be improved? The final sentence in "Brief introduction" is particularly opaque to me; I'm not sure if it's saying the oxalic acids oxidase and decarboxylase, and formyl-CoA decarboxylase, or if it's saying the compound "oxalic acid oxidase", the compound "oxalic acid decarboxylase", and the compound "formyl-CoA decarboxylase", or something else; oxidase and decarboxylase don't appear to me to be kinds of oxalic acids, but I'm completely out of my league here. Nyttend (talk) 14:15, 18 March 2017 (UTC)

The place for your question is waiting here. Read WP:BOLD. Blooteuth (talk) 14:31, 18 March 2017 (UTC)

That's completely useless. (1) With a very new article, and an orphaned one at that, nobody's going to see the talk page. (2) If you'd looked at the article history, you would have seen that I already made these changes; I'm asking for someone knowledgeable to look over the changes. Do not offer answers on topics on which you are not qualified. Nyttend (talk) 16:48, 18 March 2017 (UTC)

I made a few changes to the article and created the talk page. One change was to remove the erroneous and confusing "polymer proteins", which I hope makes the final sentence of the introduction clearer.--Wikimedes (talk) 05:59, 19 March 2017 (UTC)

Writing articles like this takes time - but some of the scut work like transferring references from other Wikipedia articles cited should be easy, if not glamorous. I sympathize with the original poster just wanting to link the articles rather than screw around grabbing references out of them. There are some things like Oxalate CoA-transferase and Oxalyl-CoA decarboxylase that would bear mentioning, and it seems inevitable to mention bacteria responsible for protection against kidney stones, but also oxalate growth medium (maybe there's a better name?) used to test for certain bacteria. This can be a substantial article... Wnt (talk) 23:56, 18 March 2017 (UTC)

I couldn't transfer the references because I couldn't find them; none of the articles I checked, none of the articles mentioned in the citations, appeared to have such citations. My question with the links was basically "which of these articles covers the intended meaning in this spot of text" and thus "which ones should be linked here". Nyttend (talk) 00:32, 19 March 2017 (UTC)