Question

What is the gas constant

Answer 1

$R \approx 8.314 \, \text{J mol}^{-1}\text{K}^{-1}$

Answer 2

The gas constant, usually denoted by $R$, appears in the ideal gas law given by

$$PV = nRT.$$

Its accepted value in SI units is approximately

$$R = 8.314 \, \text{J mol}^{-1}\text{K}^{-1}.$$

Using the ideal gas equation $PV = nRT$, the constant $R$ is defined. Its SI unit is joules per mole per Kelvin.