Values of R	Units (V·P·T-1·n-1)
8. The ideal gas law is the Equation of state of a hypothetical Ideal gas, first stated by Benoît Paul Émile Clapeyron in 1834 314472	J·K-1·mol-1
0. The joule (written in lower case ˈdʒuːl or /ˈdʒaʊl/ (symbol J) is the SI unit of Energy measuring heat, Electricity 0820574587	L·atm·K-1·mol-1
8. The litre or liter (see spelling differences) is a unit of Volume. The Standard atmosphere is an international reference pressure defined as 101325 Pa and formerly used as unit of Pressure (symbol atm The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The mole (symbol mol) is a unit of Amount of substance: it is an SI base unit, and almost the only unit to be used to measure this 20574587 × 10-5	m3·atm·K-1·mol-1
8. 314472	cm3·MPa·K-1·mol-1
8. 314472	L·kPa·K-1·mol-1
8. 314472	m3·Pa·K-1·mol-1
62. 3637	L·mmHg·K-1·mol-1
62. The torr (symbol Torr) is a non- SI unit of Pressure defined as 1/760 of an atmosphere. 3637	L·Torr·K-1·mol-1
83. 14472	L·mbar·K-1·mol-1
1. 987	cal·K-1·mol-1
6. This article is about the unit of energy For its use in Nutrition and Food labelling regulations, see the article on Food energy. 132440	lbf·ft·K-1·g·mol-1
10. The foot-pound force, or simply foot-pound (symbol ft·lbf or ft·lb) is a unit of work or Energy (a scalar 7316	ft3·psi· °R-1·lb-mol-1
0. Rankine is a thermodynamic (absolute temperature scale named after the Scottish Engineer and Physicist William John Macquorn Rankine The mole (symbol mol) is a unit of Amount of substance: it is an SI base unit, and almost the only unit to be used to measure this 7302	ft3·atm·°R-1·lb-mol-1
1716 (Air only)	ft·lb·°R-1·slug-1
286. The slug is an English unit of Mass. It is a mass that accelerates by 1 ft/s² when a force of one Pound-force (lbf is exerted on it 9 (Air only)	N·m·kg-1·K-1
286. 9 (Air only)	J·kg-1·K-1
999	ft3·mmHg·K-1·lb-mol-1

The gas constant (also known as the molar, universal, or ideal gas constant, usually denoted by symbol R) is a physical constant which is featured in a large number of fundamental equations in the physical sciences, such as the ideal gas law and the Nernst equation. A physical Constant is a Physical quantity that is generally believed to be both universal in nature and constant in time The ideal gas law is the Equation of state of a hypothetical Ideal gas, first stated by Benoît Paul Émile Clapeyron in 1834 In Electrochemistry, the Nernst equation is an equation which can be used (in conjunction with other information to determine the equilibrium Reduction potential It is equivalent to the Boltzmann constant, but expressed in units of energy (i. Bridge from macroscopic to microscopic physics Boltzmann's constant k is a bridge between Macroscopic and microscopic physics In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός e. the pressure-volume product) per kelvin per mole (rather than energy per kelvin per particle). The kelvin (symbol K) is a unit increment of Temperature and is one of the seven SI base units The Kelvin scale is a thermodynamic The mole (symbol mol) is a unit of Amount of substance: it is an SI base unit, and almost the only unit to be used to measure this

Its value is:

R = 8. 314472(15) J · K^-1 · mol^-1

The two digits in parentheses are the uncertainty (standard deviation) in the last two digits of the value. Brackets are Punctuation marks used in pairs to set apart or interject text within other text In Probability and Statistics, the standard deviation is a measure of the dispersion of a collection of values

The gas constant occurs in the simplest equation of state, the ideal gas law, as follows:

where:

is the absolute pressure

is absolute temperature

is the volume the gas occupies

is the amount of gas (the number of gas molecules, usually in moles)

is the molar volume

The gas constant has the same units as specific entropy. In Physics and Thermodynamics, an equation of state is a relation between state variables More specifically an equation of state is a thermodynamic The ideal gas law is the Equation of state of a hypothetical Ideal gas, first stated by Benoît Paul Émile Clapeyron in 1834 Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface Thermodynamic temperature is the absolute measure of Temperature and is one of the principal parameters of Thermodynamics. The mole (symbol mol) is a unit of Amount of substance: it is an SI base unit, and almost the only unit to be used to measure this The molar volume, symbol V m is the Volume occupied by one mole of a substance ( Chemical element or Chemical compound) In Thermodynamics (a branch of Physics) entropy, symbolized by S, is a measure of the unavailability of a system ’s Energy

Contents 1 Relationship with the Boltzmann constant 2 Specific gas constant 3 US Standard Atmosphere 4 See also 5 References 6 External links

Relationship with the Boltzmann constant

The Boltzmann constant k_B (often abbreviated k) may be used in place of the gas constant by working in pure particle count, N, rather than number of moles, n, since

,

where N_A is Avogadro's number. Bridge from macroscopic to microscopic physics Boltzmann's constant k is a bridge between Macroscopic and microscopic physics The Avogadro constant (symbols L, N A also called Avogadro's number, is the number of "elementary entities" (usually Atoms For example, the ideal gas law in terms of Boltzmann's constant is .

Specific gas constant

The specific gas constant of a gas or a mixture of gases () is given by the universal gas constant, divided by the molar mass (M) of the gas/mixture. Molar mass, symbol M, is the Mass of one mole of a substance ( Chemical element or Chemical compound)

It is common to represent the specific gas constant by the symbol R. In such cases the context and/or units of R should make it clear as to which gas constant is being referred to. For example, the equation for the speed of sound is usually written in terms of the specific gas constant. Sound is a vibration that travels through an elastic medium as a Wave.

The specific gas constant of dry air is

US Standard Atmosphere

The US Standard Atmosphere, 1976 (USSA1976) defines the Universal Gas Constant as:^[1][2]

The USSA1976 does recognize, however, that this value is not consistent with the cited values for the Avogadro constant and the Boltzmann constant. Temperature and layers The temperature of the Earth's atmosphere varies with altitude the mathematical relationship between temperature and altitude varies among five The US Standard Atmosphere is a series of models that define values for atmospheric Temperature, Density, pressure and other properties over ^[2] This disparity is not a significant departure from accuracy, and USSA1976 uses this value of R for all the calculations of the standard atmosphere. When using the ISO value of R, the calculated pressure increases by only 0. 62 pascals at 11,000 meters (the equivalent of a difference of only 0. 174 meters – or 6. 8 inches) and an increase of 0. 292 pascals at 20,000 meters (the equivalent of a difference of only 0. 338 meters – or 13. 2 inches).

See also

• Boltzmann constant

References

1. ^ Standard Atmospheres. Bridge from macroscopic to microscopic physics Boltzmann's constant k is a bridge between Macroscopic and microscopic physics Retrieved on 2007-01-07. Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Events 1325 - Alfonso IV becomes King of Portugal. 1558 - France takes Calais, the last continental
2. ^ ^{a b} U.S. Standard Atmosphere, 1976, U. S. Government Printing Office, Washington, D. C. , 1976 (Linked file is 17 MiB).

External links

• Gas Constant CODATA Value at NIST
• Boltzmann Constant CODATA Value at NIST

© 2009 citizendia.org; parts available under the terms of GNU Free Documentation License, from http://en.wikipedia.org
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic