Talk:Boric acid

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What makes boron compounds toxic to insects but not mammals? njh 06:15, 6 January 2006 (UTC)

Boric acid IS toxic to mammals. It's just not toxic enough that incidental contact is of any concern.

The above is false. Boric acid used as antiseptic eyedrops in infants is dangerous as enough is absorbed to cause hemolysis of the red blood cells to cause kidney problems and anemia.

If boric acid is used on injured skin enough can be absorbed to do the same thing in adults, it is a basic pharmacological quality of boric acid to do this. My only guess is that people with a financial stake in boric acid would recklessly give out such information to support its uses in people. I am tired of trying to correct this misinformation, see Goodman and Gillman's: Pharmacological Basis of Theraputics, or any other Pharmacology text that is commonly used in medical schools to support these facts.

If, however, a pet or child, for example, were to suddenly ingest a non-trivial amount (e.g. a handful or even a spoonful) all at once, it would be cause to seek immediate emergency care.

In other words, if you are handling it and accidentally consume some of the free-floating dust, it is unlikely to harm you because it will be quickly processed and evacuated. If, however, boric acid spilled into your sugar container, and you blindly took a big gulp of it thinking you were eating a big spoon of sugar, you would be wise to immediately call for emergency care. Note that the same would be true if you consumed an abnormally large amount of salt (referencing the comparison in the article) in one big gulp by accident. I don't know what the exact numbers are, but I believe that around 20g of either is enough of a concentration to overload the kidneys and cause fatal poisoning in an adult. On the flipside, 20g is also very, very difficult to consume unintentionally.

The mechanism in insects is twofold: firstly, insects have a much smaller mass than most mammals and ingesting smaller amounts results in a larger percentage of their mass being comprised of the chemical compound. Secondly, insect metabolisms and chemical composition are significantlyl different than those of mammals, and they are simply susceptible to different poisons. You don't see that disparity occur as often between different mammalian species because the genetic composition differs less between, for example, a dog and its owner than between that owner and a silverfish he's attempting to kill. --216.153.178.21 19:04, 18 July 2006 (UTC)

[edit] B(OH)₄⁻

What is the name of the anion B(OH)₄⁻? I can't find a definitive answer anywhere! The only name I've seen is borate, but that is also used to refer to BO₃³⁻. The only reason I want to know is because I've made an image of the structure of this anion and before I can upload it, I need to give it a filename!

Cheers

Ben 22:43, 27 December 2006 (UTC)

According to CAS: CA Index Name: Borate(1-), tetrahydroxy- (9CI); Other Names: Borate (BO45-), tetrahydrogen (8CI); Borate (B(OH)41-); Tetrahydroxoborate(1-); Tetrahydroxyborate(1-).

My favorite among those would be tetrahydroxyborate. Itub 23:17, 27 December 2006 (UTC)

The "bible" (Holleman and Wiberg) also say tetrahydroxyborate. It explains that B(OH)3 (orthoboric acid, also called boric acid) is a very weak Lewis acid (not Bronsted) and apparently picks up the extra hydroxide somewhat reluctantly.--Smokefoot 23:27, 27 December 2006 (UTC)

Good stuff. Thanks, gentlemen. I have, accordingly, created the article tetrahydroxyborate. See if you might like to contribute to it.

Ben 23:49, 27 December 2006 (UTC)

What makes you think that BO₃³⁻ actually exists? Both boric acid and borate explain that H₃BO₃ does not dissociate protolytically: the acid equilibrium is:

B(OH)₃ + H₂O ⇌ B(OH)₄⁻ + H⁺

K_a = 5.8x10⁻¹⁰ mol/l; pK_a = 9.24.

NaB(OH)₄ is stoichiometrically equivalent to NaBO₂·2H₂O, and will dehydrate to sodium metaborate if you heat it strongly enough. But sodium borate is not Na₃BO₃, at least as far as I've ever seen (although a fusion of the mixed oxides would be quite interesting: it would probably give... a mixed oxide!) Physchim62 (talk) 00:17, 28 December 2006 (UTC)

I read this in Greenwood & Earnshaw:

monomeric triangular BO₃ units exist in rare-earth orthoborates, M^IIIBO₄

so I assumed BO₃³⁻, whether it really exists or not aside, was named orthoborate.

Would it not be possible to form BO₃³⁻ fleetingly in the gas phase? If so, the species would need a name.

Even if BO₃³⁻ doesn't exist, that doesn't necessarily mean B(OH)₄⁻ assumes the title borate. Considering the immense structural diversity of boron oxoanions, I thought a common one like B(OH)₄⁻ would have its own distinct name.

At least I had a term to name my images and the article!

Ben 00:49, 28 December 2006 (UTC)

FWIW, BO₃³⁻ is listed by Chemical Abstracts as "borate" (also "orthoborate") and has its own registry number. I don't know for sure under which conditions it exists, but certainly tetrahydroxyborate is a less-ambiguous name for B(OH)₄⁻. Itub 00:57, 28 December 2006 (UTC)

Fair enough, more details for borate then :) ! Physchim62 (talk) 07:28, 28 December 2006 (UTC)