nRT

nRT is a term found in thermodynamics and physical chemistry, most commonly appearing in the ideal gas law PV = nRT. In this context, n is the amount of substance in moles, R is the universal gas constant, and T is the absolute temperature in kelvin. For an ideal gas, the product nRT equals the pressure times the volume, so PV = nRT.

The universal gas constant R links microscopic energy scales to macroscopic measurements. Its value is 8.314462618 J/(mol·K). In other unit systems, R can be written as 0.082057366 L·atm/(mol·K) or 8.314462618 × 10^−3 kJ/(mol·K). R is related to Boltzmann's constant kB and Avogadro's number NA by R = kB·NA, connecting microscopic particle behavior to bulk gas properties.

Temperature must be expressed in kelvin for nRT to be dimensionally consistent. If temperature is given in Celsius, conversion T(K) = T(°C) + 273.15 is required.

Applications of nRT include calculating gas volumes, pressures, and moles in chemical reactions, engineering calculations for reactors and propulsion, and educational demonstrations of gas behavior. The ideal gas law assumes ideal behavior—point particles with no interactions—so real gases deviate at high pressures or low temperatures. Such deviations are described by more complex equations of state (for example, including a compressibility factor Z, where Z = PV/(nRT)).

In summary, nRT is the product of the amount of substance, the gas constant, and temperature, and it governs the relationship PV = nRT for ideal gases.