Question

Value of universal gas constant (R) is same for all gases. What is its physical significance?

Answer 1

Unit of R depends upon those units in which p, V and T are measured, R-pV/nT.

If pressure is measured in Pascal, per mole volume is measured in m3 and temperature is measured in Kelven then. Units of ‘R’ are Pam3K–1 mol–1 or J mol–1 K–1. Jule is the unit of work done so ‘R’ is work done per mole per kelvin.For one mole, therefore, pV/T = R. The dimensions of the universal gas constant R are energy per degree per mole. In the metre-kilogram-second system, the value of R is 8.3144598 joules per kelvin (K) per mole.

Answer 2

The gas constant is also termed as the molar gas constant, universal gas constant or“ideal gas constant, indicated by the symbol R, and is equivalent to the Boltzmann constant, but expressed in units of energy per mole, i.e., pressure-volume product, instead of energy per particle.

The unit of R depends on the units measured in p, V, and T, R-pV/nT

If the pressure in Pascal is measured, the mole volume is measured in ${ m }^{ 3 }$ and the temperature in Kelvin is measured.

'R' units are Pa. ${ m }^{ 3 }{ K }^{ -1 }mo{ l }^{ -1 }$ or $J { mol }^{ -1 }{ K }^{ -1 }$