標準狀況

標準狀況（英語：standard temperature and pressure, STP，標準溫度與標準壓力），簡稱「標況」。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強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。

在化學領域，國際純化學和應用化學聯合會（IUPAC）在1982年改變了標準溫度和標準壓力（STP）的定義：

在1982年以前，標準狀況定義為0 ℃（273.15 K）、101325 / 10⁵ Pa（1 atm）。1莫耳的理想氣體在STP下占有的體積為22.414升（L）。

自1982年以來，標準狀況定義為0 ℃（273.15 K）、100kPa，這樣的定義接近海平面上水的冰點。1莫耳的理想氣體在STP下占有的體積為22.710953（21）L(CODATA 2010)，為標準莫耳體積（standard molar volume）。這是區別一般條件而制定的標準。

歷史上由巴黎制定的通行歐洲的舊制標準如下：

壓力p = 1 atm = 101325 帕斯卡 = 1013.25 hPa = 101.325 kPa = 1.01325 bar.
溫度T = 298.15 K ≙ 25 °C，空氣密度ρ = 1.184 kg/m³.

現在也使用T = 293.15 K ≙ 20 °C 空氣密度ρ = 1.204 kg/m³.

在化學和生物化學中另外還包括定義的觀察反應物濃度，一般情況下為1mol/L（1 M）。^{[來源請求]}在生物化學中只有氫離子例外（H⁺）。限定pH為7，即10^-7 mol/l H⁺離子濃度用於准生理條件描述，肌體條件，細胞內部條件等。

當前使用的標準狀況

世界各地的組織目前正在使用許多不同的標準狀況定義。下表列出了其中的一些。其中一些組織過去使用過其他標準。例如，自1982年以來，IUPAC將標準參考條件定義為0°C和100 kPa（1 bar），而其舊標準為0°C和101.325 kPa（1 atm）。

**標準狀況參考條件**
溫度	絕對壓力	相對濕度	出版或創立者
°C	kPa	% RH	出版或創立者
0	100.000		IUPAC（1982年之後正在使用的定義）
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：加拿大電力和燃氣檢驗法
SATP：標準的環境壓力和溫度
SCAQMD：加州南海岸空氣品質管理區

氣體莫耳體積

當表示氣體的莫耳體積時，要指明適用的溫度和壓力條件。在不指明溫度和壓力條件的情況下，說明氣體的莫耳體積幾乎沒有意義並且可能引起混淆。

通過使用理想氣體定律，可以計算在標準狀況下的氣體莫耳體積。任何理想氣體的莫耳體積可以在各種標準參考條件下計算，如下所示：

V_m = 8.3145 × 273.15 / 101.325 = 22.414 dm³/mol （在 0 °C 和 101.325 kPa 下）
V_m = 8.3145 × 273.15 / 100.000 = 22.711 dm³/mol （在 0 °C 和 100 kPa 下）
V_m = 8.3145 × 298.15 / 101.325 = 24.466 dm³/mol （在25 °C 和 101.325 kPa 下）
V_m = 8.3145 × 298.15 / 100.000 = 24.790 dm³/mol （在25 °C 和 100 kPa 下）
V_m = 10.7316 × 519.67 / 14.730 = 378.61 ft³/lbmol （在60 °F 和 14.73 psi 下）

參看

吉布斯能

參考資料

^ NIST. NIST Standard Reference Database 7 – NIST Electron and Positron Stopping Powers of Materials Database. 1989 [2008-07-25]. （原始內容存檔於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] （英語）.
^ ^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 （頁面存檔備份，存於網際網路檔案館）
^ "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 （頁面存檔備份，存於網際網路檔案館）
^ "Standards of Performance for New Sources", 40 CFR--Protection of the Environment, Chapter I, Part 60, Section 60.2, 1990 New Source Performance Standards （頁面存檔備份，存於網際網路檔案館）
^ 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. （原始內容存檔 (PDF)於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 （頁面存檔備份，存於網際網路檔案館）
^ "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 網際網路檔案館的存檔，存檔日期2007-10-28.
^ ^12.0 ^12.1 The SI Metric System of Units and SPE Metric Standard 網際網路檔案館的存檔，存檔日期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 網際網路檔案館的存檔，存檔日期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 網際網路檔案館的存檔，存檔日期2008-12-19.
^ "Annual Statistical Bulletin", 2004, Editor-in-chief: Dr. Omar Ibrahim, Organization of the Petroleum Exporting Countries, Vienna, Austria OPEC Statistical Bulletin 網際網路檔案館的存檔，存檔日期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 （頁面存檔備份，存於網際網路檔案館）
^ Sierra Bullets L.P. Chapter 3 – Effects of Altitude and Atmospheric Conditions. Rifle and Handgun Reloading Manual, 5th Edition. [2008-12-20]. （原始內容存檔於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 （頁面存檔備份，存於網際網路檔案館）
^ 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 （頁面存檔備份，存於網際網路檔案館）
^ ANSI/AMCA Standard 210, "Laboratory Methods Of Testing Fans for Aerodynamic Performance Rating", as implied here: http://www.greenheck.com/pdf/centrifugal/Plug.pdf （頁面存檔備份，存於網際網路檔案館） 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 （頁面存檔備份，存於網際網路檔案館）" from the IUPAC Gold Book.
"Standard conditions for gases （頁面存檔備份，存於網際網路檔案館）" from the IUPAC Gold Book.
Molar volume of an ideal gas （頁面存檔備份，存於網際網路檔案館）（CODATA 2010 values）
Online ICAO Atmosphere calculator for aviators http://www.aviation.ch/tools-atmosphere.asp （頁面存檔備份，存於網際網路檔案館）

[NISTDataBase7-1] NIST. NIST Standard Reference Database 7 – NIST Electron and Positron Stopping Powers of Materials Database. 1989 [2008-07-25]. （原始內容存檔於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）.

[ISO10780-2] 14:00-17:00. ISO 10780:1994. ISO. [2022-10-15] （英語）.

[Handbook-3] 3.0 ^3.1 Robert C. Weast (Editor). Handbook of Physics and Chemistry 56th. CRC Press. 1975: F201–F206. ISBN 0-87819-455-X.

[ISO13443-4] 4.0 ^4.1 "Natural gas – Standard reference conditions", ISO 13443, International Organization for Standardization, Geneva, Switzerland ISO Standards Catalogue （頁面存檔備份，存於網際網路檔案館）

[EEA-5] "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]}

[EGIA-6] 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 （頁面存檔備份，存於網際網路檔案館）

[NSPS-7] "Standards of Performance for New Sources", 40 CFR--Protection of the Environment, Chapter I, Part 60, Section 60.2, 1990 New Source Performance Standards （頁面存檔備份，存於網際網路檔案館）

[NISTJournal-8] 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. （原始內容存檔 (PDF)於2022-10-21）.

[NAAQS-9] "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 （頁面存檔備份，存於網際網路檔案館）

[NBS-10] "Table of Chemical Thermodynamic Properties", National Bureau of Standards（NBS）,Journal of Physics and Chemical Reference Data, 1982, Vol. 11, Supplement 2.

[CAGI-11] "Glossary", 2002, Compressed Air and Gas Institute, Cleveland, OH, USA Glossary 網際網路檔案館的存檔，存檔日期2007-10-28.

[SPE-12] 12.0 ^12.1 The SI Metric System of Units and SPE Metric Standard 網際網路檔案館的存檔，存檔日期2008-12-20. 1984, Richardson, TX, USA（Notes for Table 2.3 on page 25 define standard cubic foot and standard cubic meter）

[OSHA-13] "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 網際網路檔案館的存檔，存檔日期2006-07-19.

[SCAQMD-14] "Rule 102, Definition of Terms（Standard Conditions）", Amended December 2004, South Coast Air Quality Management District, Los Angeles, California, USA SCAQMD Rule 102 網際網路檔案館的存檔，存檔日期2008-12-19.

[OPEC-15] "Annual Statistical Bulletin", 2004, Editor-in-chief: Dr. Omar Ibrahim, Organization of the Petroleum Exporting Countries, Vienna, Austria OPEC Statistical Bulletin 網際網路檔案館的存檔，存檔日期2008-12-19.

[EIA-16] "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 （頁面存檔備份，存於網際網路檔案館）

[ArmyStdMetro-17] Sierra Bullets L.P. Chapter 3 – Effects of Altitude and Atmospheric Conditions. Rifle and Handgun Reloading Manual, 5th Edition. [2008-12-20]. （原始內容存檔於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 （頁面存檔備份，存於網際網路檔案館）

[18] 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.

[ISO3977-2-19] "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 （頁面存檔備份，存於網際網路檔案館）

[AMCA-20] ANSI/AMCA Standard 210, "Laboratory Methods Of Testing Fans for Aerodynamic Performance Rating", as implied here: http://www.greenheck.com/pdf/centrifugal/Plug.pdf （頁面存檔備份，存於網際網路檔案館） when accessed on October 17, 2007

[AMCA_note-21] 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)

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