The Ideal Gas Constant

Professor John M. Cimbala

Students are often confused by the units of the ideal gas constant. This confusion is compounded by the fact that there are two forms of the gas constant: the universal gas constant and the specific gas constant. To avoid confusion and error, these are defined below, along with their relationships with mol and molecular weight. For completeness, numerical values are given in both S.I. and English units.

Mol, Atomic weight, and Molecular weight

Universal gas constant and ideal gas law

Specific gas constant