Talk:Orthosilicic acid

Latest comment: 3 years ago by Timo Moilanen in topic Caveat Emptor

Caveat Emptor edit

Don't put too much faith in the claims presented here. The chemistry in 1922 was in some ways NOT done well (with modern standards as their measure) (in other ways, the chemistry back then was better than is typical today, but I digress). It is better, imho, to consider orthosilicic acid as a formal designation for a group of silicon, oxygen, and hydrogen compounds which exist in pure water. Their exact structures depend on conditions and probably depend on their history, the precise elemental composition will also vary.174.131.63.233 (talk) 17:38, 10 June 2018 (UTC)Reply

What you are describing is silicic acid, which is indeed a soup of infinitely many molecular structures in dynamic equilibrium. However, orthosilicic acid is a specific molecule, and it (or its anions) is arguably the form that SiO
2
takes in very dilute solutions (such as seawater). In fact, the orthosilicate anion SiO4−
4
is well characterized and stable in salts, and ditto for the orthosilicate group in esters. The pure acid itself looks like it could be isolated in extreme conditions, like interstellar space or a frozen argon matrix.
Chemists in 1922 did not have all the fancy methods that are used today to discover molecular structure, true. However, their methods (like freezing point depression) still would let them determine whether silica was present in isolated [SiO
2+x
H
x-y
]
y units (silica, orthosilicic acid, or metasilicic acid, and their anions) as opposed to pyrosilicic/disilicic and larger units. And then they could be able to tell that, in the conditions of the experiment, the 1-silicon and 2-silicon species took many minutes to break or polymerize.
Thus I think that old papers do not deserve to be ignored, even in a complicated field like this one. --Jorge Stolfi (talk) 22:37, 11 June 2018 (UTC)Reply

The color bar for dissolved silica is in m mol/m3, that is a small stone (several mm ) solved in 1m3 of water. Compared to silicic acid Britannica (2 µmol/m3 for algae "bloom") this is 10.000 times the concentration. Since this is an acute environment factor (declining) I think "high rank" correction need be done. Your's Timo Moilanen.Timo Moilanen (talk) 07:44, 20 April 2021 (UTC)Reply