Silica Gel

Catalog	ACM112926008
CAS	112926-00-8
Structure
Category	Flocculant
Description	Silica gel is a granular, vitreous, porous form of silicon dioxide made synthetically from sodium silicate. Silica gel contains a nano-porous silica micro-structure, suspended inside of a liquid. Most applications of silica gel require it to be dried, in which case it is called silica xerogel. For practical purposes, silica gel is often interchangeable with silica xerogel. Silica xerogel is tough and hard; it is more solid than common household gels like gelatin or agar. It is a naturally occurring mineral that is purified and processed into either granular or beaded form. As a desiccant, it has an average pore size of 2.4 nanometers and has a strong affinity for water molecules.Silica gel is most commonly encountered in everyday life as beads in a small (typically 2 x 3 cm) paper packet. In this form, it is used as a desiccant to control local humidity to avoid spoilage or degradation of some goods. Because silica gel can have added chemical indicators (see below) and absorbs moisture very well, silica gel packets usually bear warnings for the user not to eat the contents.
Synonyms	Dry Silica Gel
IUPAC Name	Dioxosilane
Molecular Weight	60.09
Molecular Formula	SiO2
Canonical SMILES	O=[Si]=O
InChI	InChI=1S/O2Si/c1-3-2
InChI Key	VYPSYNLAJGMNEJ-UHFFFAOYSA-N
Boiling Point	4046 °F at 760 mm Hg (NIOSH, 2016);4046 °F;2230 °C;>2200 °C;2230 °C;2230 °C;2230 °C;4046°F
Melting Point	3110 °F (NIOSH, 2016);Mp 1716-1736 °;3110 °F;1710 °C;1716-1736°C;1710 °C;1703 °C;1610 °C;1713 °C;3110°F
Density	2.2 (NIOSH, 2016);2.2 @ 25 °C;2.6;2.3 g/cm³;2.3 g/cm³;2.6 g/m3;2.3 g/cm³;2.20
Solubility	Insoluble (NIOSH, 2016);Insoluble;Silica is rather poorly soluble in water although solubility is higher for the amorphous than for the crystalline morphologies. ... The external amorphous layer in quartz is more soluble than the crystalline underlying core.;AMORPHOUS IS SOL IN ALKALIES, ESP WHEN FINELY DIVIDED;Practically insoluble in water or acids. Dissolves readily in HF, forming silicon tetrafluoride.;Very slightly sol in alkali.;Soluble in hot potassium hydroxide and hot sodium hydroxide solutions. Insoluble in ethanol.;Silica is rather poorly soluble in water and solubility is lower for the crystalline than for the amorphous morphologies. ...Solubility increases with temperature and pH and is affected by the presence of trace metals. Particle size influences the rate of solubility.;The external amorphous layer in quartz (the Beilby layer) is more soluble than the crystalline underlying core.;Solubility in water: none;Solubility in water: none;Solubility in water: none;Solubility in water: none;Insoluble
EC Number	262-373-8
MDL Number	MFCD00011232
Vapor Pressure	0 mm Hg (approx) (NIOSH, 2016);approx 0 mm Hg;10 mm Hg @ 1732 °C;0 mmHg (approx)

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