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The first crystalline silicic acid was prepared from the phyllosilicate natrosilite (Na 2 Si 2 O 5) in 1924. More than 15 crystalline acids are known and comprise at least six modifications of H 2 Si 2 O 5 .
Orthosilicic acid (/ ˌ ɔːr θ ə s ɪ ˈ l ɪ s ɪ k /) is an inorganic compound with the formula Si(O H) 4. Although rarely observed, it is the key compound of silica and silicates and the precursor to other silicic acids [H 2x SiO x+2] n. Silicic acids play important roles in biomineralization and technology.
Silica gel was in existence as early as the 1640s as a scientific curiosity. [5] It was used in World War I for the adsorption of vapors and gases in gas mask canisters.The synthetic route for producing silica gel was patented in 1918 by Walter A. Patrick, a chemistry professor at Johns Hopkins University.
The subunits of colloidal silica particles are typically in the range of 1 to 5 nm. Whether or not these subunits are joined depends on the conditions of polymerization. Initial acidification of a water-glass (sodium silicate) solution yields Si(OH) 4. If the pH is reduced below 7 or if salt is added, then the units tend to fuse together in chains.
Method 2 requires adding an ester (reaction product of an acid and an alcohol) to the mixture of sand and sodium silicate before it is placed into the molding box or core box. As the ester hydrolyzes from the water in the liquid sodium silicate, an acid is released which causes the liquid sodium silicate to gel.
Here, the silicic acid H 4 SiO 4, or Si(OH) 4, which is equivalent to SiO 2 · 2 H 2 O represents hydrous or amorphous silica for the sake of simplicity in aqueous chemistry. Indeed, the term silicic acid has traditionally been used as a synonym for silica, SiO 2. Strictly speaking, silica is the anhydride of orthosilicic acid, Si(OH) 4.
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In horticulture, potassium silicate is used as a soluble source of potassium and silica.It makes the growing medium more alkaline. It is also used as a supplement (in conjunction with normal fertilizer) for the numerous benefits that increasing the availability of silicon compounds has.