Search results
Results From The WOW.Com Content Network
Boric acid is a weak acid, with pK a (the pH at which buffering is strongest because the free acid and borate ion are in equal concentrations) of 9.24 in pure water at 25 °C. But apparent p K a is substantially lower in swimming pool or ocean waters because of interactions with various other molecules in solution.
This page provides supplementary chemical data on boric acid. Thermodynamic properties. Phase behavior Triple point? K (? °C), ? Pa Critical point? K (? °C), ?
Zinc borate refers to a family of inorganic compounds consisting of borate of zinc.They are white solids with the formulas 4ZnO·B 2 O 3 ·H 2 O, ZnO·B 2 O 3 ·1.12H 2 O, ZnO·B 2 O 3 ·∼2H 2 O, 6ZnO·5B 2 O 3 ·3H 2 O, 2ZnO·3B 2 O 3 ·7H 2 O, 2ZnO·3B 2 O 3 ·3H 2 O, 3ZnO·5B 2 O 3 ·14H 2 O, and ZnO·5B 2 O 3 ·4.5H 2 O.
In aqueous solution, boric acid B(OH) 3 can act as a weak Brønsted acid, that is, a proton donor, with pK a ~ 9. However, it more often acts as a Lewis acid , accepting an electron pair from a hydroxide ion produced by the water autoprotolysis : [ 11 ]
The original coral-colored Silly Putty is composed of 65% dimethylsiloxane (hydroxy-terminated polymers with boric acid), 17% silica (crystalline quartz), 9% Thixatrol ST (castor oil derivative), 4% polydimethylsiloxane, 1% decamethyl cyclopentasiloxane, 1% glycerine, and 1% titanium dioxide. [6] Silly Putty flowing through a hole
The ion occurs in boric acid solutions at neutral pH, being formed by condensation of orthoborate and tetrahydroxyborate anions: 2 B(OH) 3 + 2 [B(OH) 4] − ⇌ [B 4 O 5 (OH) 4] − 2 + 5 H 2 O. The tetraborate anion includes two tetrahedral and two trigonal boron atoms symmetrically assembled in a fused bicyclic structure.
Potassium fluoroborate is obtained by treating potassium carbonate with boric acid and hydrofluoric acid. B(OH) 3 + 4 HF → HBF 4 + 3 H 2 O 2 HBF 4 + K 2 CO 3 → 2 KBF 4 + H 2 CO 3. Fluoroborates of alkali metals and ammonium ions crystallize as water-soluble hydrates with the exception of potassium, rubidium, and cesium.
Another method is heating boric acid above ~300 °C. Boric acid will initially decompose into steam, (H 2 O (g)) and metaboric acid (HBO 2) at around 170 °C, and further heating above 300 °C will produce more steam and diboron trioxide. The reactions are: H 3 BO 3 → HBO 2 + H 2 O 2 HBO 2 → B 2 O 3 + H 2 O. Boric acid goes to anhydrous ...