Silicon dioxide
From Wikinfo
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General |
|
|---|---|
| Name | Silicon dioxide |
| Chemical formula | SiO2 |
| Appearance | Transparent solid |
|
Physical |
|
| Formula weight | 60.1 amu |
| Melting point | 1986 K (1713 °C) |
| Boiling point | 2503 K (2230 °C) |
| Density | 2.6 ×103 kg/m3 |
| Crystal structure | Quartz, cristobalite or tridymite |
| Solubility | 0.012 g in 100g water |
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Thermochemistry |
|
| ΔfH0gas | -305.43 kJ/mol |
| ΔfH0liquid | -899.86 kJ/mol |
| ΔfH0solid | -910.86 kJ/mol |
| S0gas, 1 bar | 228.98 J/mol·K |
| S0liquid, 1 bar | ? J/mol·K |
| S0solid | 41.46 J/mol·K |
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Safety | |
| Ingestion | Low hazard. |
| Inhalation | Irritation, long term exposure causes silicosis. |
| Skin | May cause irritation. |
| Eyes | May cause irritation. |
| More info | Hazardous Chemical Database |
SI units were used where possible. Unless otherwise stated, standard conditions were used. | |
Silicon dioxide also known as silica is the naturally occurring oxide of silicon, chemical formula SiO2.
It is found in nature in several forms, including sand and quartz and is also a major constituent of many minerals, including flint.
It is also manufactured in several forms including glass and silica gel. It is a major ingredient of Portland cement.
Inhaling silica dust can lead to silicosis.
References
- Adapted from the Wikipedia article, "Silicon dioxide" http://www.wikipedia.org/wiki/Silicon_dioxide August 3, 2003
