标准状况
(重定向自标准情况)
标准状况(英語:standard temperature and pressure, STP,标准温度与标准压力),简称「标况」。由於地表各處的溫度、壓力皆不同,即使是同一地點的溫度壓强也隨測量時間不同而相異,因此為研究方便,制定出描述物質特徵的標準狀況。
在化学领域,国际纯化学和应用化学联合会(IUPAC)在1982年改变了标准温度和标准压力(STP)的定义:
- 自1982年以来,标准状况定义为0 ℃(273.15 K)、100kPa,這樣的定義接近海平面上水的冰點。1摩尔的理想氣體在STP下占有的體積為22.710953(21)L(CODATA 2010),為標準摩尔體積(standard molar volume)。這是区别一般条件而制定的标准。
历史上由巴黎制定的通行欧洲的舊制標準如下:
- 压强p = 1 atm = 101325 帕斯卡 = 1013.25 hPa = 101.325 kPa = 1.01325 bar.
- 温度T = 298.15 K ≙ 25 °C,空气密度ρ = 1.184 kg/m³.
- 现在也使用T = 293.15 K ≙ 20 °C 空气密度ρ = 1.204 kg/m³.
在化学和生物化学中另外还包括定义的观察反应物浓度,一般情况下为1mol/L(1 M)。[來源請求]在生物化学中只有氢离子例外(H+)。限定pH为7,即10-7 mol/l H+离子浓度用于准生理条件描述,肌体条件,细胞内部条件等。
当前使用的标准状况
世界各地的组织目前正在使用许多不同的标准状况定义。 下表列出了其中的一些。 其中一些组织过去使用过其他标准。 例如,自1982年以来,IUPAC将标准参考条件定义为0°C和100 kPa(1 bar),而其旧标准为0°C和101.325 kPa(1 atm)。
溫度 | 絕對壓力 | 相对湿度 | 出版或創立者 |
---|---|---|---|
°C | kPa | % RH | |
0 | 100.000 | IUPAC(1982年之后正在使用的定義) | |
0 | 101.325 | IUPAC(1982年以前使用的定義)NIST[1], ISO 10780[2] | |
15 | 101.325 | 0[3][4] | ICAO's ISA,[3]ISO 13443,[4] EEA,[5] EGIA[6] |
20 | 101.325 | EPA,[7] NIST[8] | |
25 | 101.325 | EPA[9] | |
25 | 100.000 | SATP[10] | |
20 | 100.000 | 0 | CAGI[11] |
15 | 100.000 | SPE[12] | |
°F | psi | % RH | |
60 | 14.696 | SPE,[12] U.S. OSHA,[13] SCAQMD[14] | |
60 | 14.73 | EGIA,[6] OPEC,[15] U.S. EIA[16] | |
59 | 14.503 | 78 | U.S. Army Standard Metro[17][18] |
59 | 14.696 | 60 | ISO 2314, ISO 3977-2[19] |
°F | in Hg | % RH | |
70 | 29.92 | 0 | AMCA,[20][21] air density = 0.075 lbm/ft³. This AMCA standard applies only to air. |
注釋:
- EGIA:加拿大电力和燃气检验法
- SATP:标准的环境压力和温度
- SCAQMD:加州南海岸空气质量管理区
气体摩尔体积
当表示气体的摩尔体积时,要指明适用的温度和压力条件。 在不指明温度和压力条件的情况下,说明气体的摩尔体积几乎没有意义并且可能引起混淆。
通过使用理想气体定律,可以计算在标准状况下的气体摩尔体积。 任何理想气体的摩尔体积可以在各种标准参考条件下计算,如下所示:
- Vm = 8.3145 × 273.15 / 101.325 = 22.414 dm3/mol (在 0 °C 和 101.325 kPa 下)
- Vm = 8.3145 × 273.15 / 100.000 = 22.711 dm3/mol (在 0 °C 和 100 kPa 下)
- Vm = 8.3145 × 298.15 / 101.325 = 24.466 dm3/mol (在25 °C 和 101.325 kPa 下)
- Vm = 8.3145 × 298.15 / 100.000 = 24.790 dm3/mol (在25 °C 和 100 kPa 下)
- Vm = 10.7316 × 519.67 / 14.730 = 378.61 ft3/lbmol (在60 °F 和 14.73 psi 下)
参看
參考資料
- ^ NIST. NIST Standard Reference Database 7 – NIST Electron and Positron Stopping Powers of Materials Database. 1989 [2008-07-25]. (原始内容存档于2011-06-29).
If you want the program to treat the material as an ideal gas, the density will be assumed given by M/V, where M is the gram molecular weight of the gas and V is the mol volume of 22414 cm3 at standard conditions(0 deg C and 1 atm).
- ^ 14:00-17:00. ISO 10780:1994. ISO. [2022-10-15] (英语).
- ^ 3.0 3.1 Robert C. Weast (Editor). Handbook of Physics and Chemistry 56th. CRC Press. 1975: F201–F206. ISBN 0-87819-455-X.
- ^ 4.0 4.1 "Natural gas – Standard reference conditions", ISO 13443, International Organization for Standardization, Geneva, Switzerland ISO Standards Catalogue (页面存档备份,存于互联网档案馆)
- ^ "Extraction, First Treatment and Loading of Liquid & Gaseous Fossil Fuels", Emission Inventory Guidebook B521, Activities 050201 - 050303, September 1999, European Environmental Agency, Copenhagen, Denmark Emission Inventory Guidebook[永久失效連結]
- ^ 6.0 6.1 "Electricity and Gas Inspection Act", SOR/86-131(defines a set of standard conditions for Imperial units and a different set for metric units) Canadian Laws (页面存档备份,存于互联网档案馆)
- ^ "Standards of Performance for New Sources", 40 CFR--Protection of the Environment, Chapter I, Part 60, Section 60.2, 1990 New Source Performance Standards (页面存档备份,存于互联网档案馆)
- ^ Wright, J.D.; Johnson, A.N.; Moldover, M.R. Design and uncertainty analysis for a PVTt gas flow standard (PDF). Journal of Research of the National Institute of Standards and Technology. 2003-01, 108 (1) [2022-10-15]. ISSN 1044-677X. PMC 4844527 . PMID 27413592. doi:10.6028/jres.108.004. (原始内容存档 (PDF)于2022-10-21).
- ^ "National Primary and Secondary Ambient Air Quality Standards", 40 CFR--Protection of the Environment, Chapter I, Part 50, Section 50.3, 1998 National Ambient Air Standards (页面存档备份,存于互联网档案馆)
- ^ "Table of Chemical Thermodynamic Properties", National Bureau of Standards(NBS),Journal of Physics and Chemical Reference Data, 1982, Vol. 11, Supplement 2.
- ^ "Glossary", 2002, Compressed Air and Gas Institute, Cleveland, OH, USA Glossary 互联网档案馆的存檔,存档日期2007-10-28.
- ^ 12.0 12.1 The SI Metric System of Units and SPE Metric Standard 互联网档案馆的存檔,存档日期2008-12-20. 1984, Richardson, TX, USA(Notes for Table 2.3 on page 25 define standard cubic foot and standard cubic meter)
- ^ "Storage and Handling of Liquefied Petroleum Gases" and "Storage and Handling of Anhydrous Ammonia", 29 CFR--Labor, Chapter XVII--Occupational Safety and Health Administration, Part 1910, Sect. 1910.110 and 1910.111, 1993 Storage/Handling of LPG 互联网档案馆的存檔,存档日期2006-07-19.
- ^ "Rule 102, Definition of Terms(Standard Conditions)", Amended December 2004, South Coast Air Quality Management District, Los Angeles, California, USA SCAQMD Rule 102 互联网档案馆的存檔,存档日期2008-12-19.
- ^ "Annual Statistical Bulletin", 2004, Editor-in-chief: Dr. Omar Ibrahim, Organization of the Petroleum Exporting Countries, Vienna, Austria OPEC Statistical Bulletin 互联网档案馆的存檔,存档日期2008-12-19.
- ^ "Natural Gas Annual 2004", DOE/EIA-0131(04),December 2005, U.S. Department of Energy, Energy Information Administration, Washington, D.C., USA Natural Gas Annual 2004 (页面存档备份,存于互联网档案馆)
- ^ Sierra Bullets L.P. Chapter 3 – Effects of Altitude and Atmospheric Conditions. Rifle and Handgun Reloading Manual, 5th Edition. [2008-12-20]. (原始内容存档于2006-03-09)."Effects of Altitude and Atmospheric Conditions", Exterior Ballistics Section, Sierra's "Rifle and Handgun Reloading Manual, 5th Edition", Sedalia, MO, USA Exterior Ballistics (页面存档备份,存于互联网档案馆)
- ^ The pressure is specified as 750 mmHg. However, the mmHg is temperature dependant, as mercury expands as temperature goes up. Here the values for the 0-20 °C range are given.
- ^ "Gas turbines – Procurement – Part 2: Standard reference conditions and ratings", ISO 3977-2:1997 and "Gas turbines - Acceptance tests", ISO 2314:1989, Edition 2, International Organization for Standardization, Geneva, Switzerland ISO (页面存档备份,存于互联网档案馆)
- ^ ANSI/AMCA Standard 210, "Laboratory Methods Of Testing Fans for Aerodynamic Performance Rating", as implied here: http://www.greenheck.com/pdf/centrifugal/Plug.pdf (页面存档备份,存于互联网档案馆) when accessed on October 17, 2007
- ^ The standard is given as 29.92 inHg at an unspecified temperature. This most likely corresponds to a standard pressure of 101.325 kPa, converted into ~29.921 inHg at 32 °F)
外部連結
- "STP (页面存档备份,存于互联网档案馆)" from the IUPAC Gold Book.
- "Standard conditions for gases (页面存档备份,存于互联网档案馆)" from the IUPAC Gold Book.
- Molar volume of an ideal gas (页面存档备份,存于互联网档案馆)(CODATA 2010 values)
- Online ICAO Atmosphere calculator for aviators http://www.aviation.ch/tools-atmosphere.asp (页面存档备份,存于互联网档案馆)