General
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|
|---|---|
| Name | Silicon dioxide |
| Chemical formula | SiO2 |
| Appearance | Transparent solid |
Physical
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| 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 |
Thermochemistry
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|
| 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 |
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. | |
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 (in colorless high purity form called fused silica) and silica gel. It is a major ingredient of Portland cement.
Inhaling silica dust can lead to silicosis.