(physics) the universal constant in the gas equation: pressure times volume = R times temperature; equal to 8.3143 joules per kelvin per mole

constant used in the Nernst equation.

A proportionality constant between the product of the pressure and volume of a gas and the product of the number of moles and temperature of the gas.

the proportionality constant in the equation of state for ideal gases; for dry air, the gas constant is 287.054 joules per kilogram per Kelvin

The constant factor in the equation of state for ideal gases. The universal gas constant is The gas constant for a particular gas is where is the molecular weight of the gas. For a mixture, the "molecular weight" is a weighted mean of the molecular weights of the components: where are the molecular weights of the gases, and are their masses relative to the total mass of the mixture. The gas constant for dry air is The gas constant for water vapor is For moist air, the variable percentage of water vapor is taken into account by retaining the gas constant for dry air while using the virtual temperature in place of the temperature. See also Boltzmann's constant.

Having a numerical value equal to 8.314 kJmol-1K-1, the gas constant is effectively a molarheat capacity.

Values of R 8.314472 J · K-1 · mol-1 0.0820574587 L · atm · K-1 · mol-1 8.20574587 x 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 62.3637 L · Torr · K-1 · mol-1 83.14472 L · mbar · K-1 · mol-1 1.987 cal · K-1 · mol-1 6.132439833 lbf · ft · K-1 · g · mol-1 34.7704 ft³ · psi · °R-1 · lb · mol-1 8.63 x 10-5 eV · atom-1 · Kelvin-1