Sackur-Tetrode equation

The Sackur-Tetrode calculator compute the Sackur-Tetrode value based on the volume, number of particles, internal energy and mass of an ideal gas.

INSTRUCTIONS: Choose units and enter the following:

• (V) Volume of gas
• (N) Number of particles in gas
• (U) Internal energy of gas
• (m) Mass of a gas particle

Sackure-Tetrode (S/kN): The calculator returns the value as a real number.   NOTE, the results of this calculator have NOT been independently verified.  Verification or error reports are requested.  Please do so via the vCalc feed-back channels.

The Math / Science

The Sackur–Tetrode equation is an expression for the entropy of a monatomic classical ideal gas which incorporates quantum considerations which give a more detailed description of its regime of validity.  The Sackur–Tetrode equation is named for Hugo Martin Tetrode[1] (1895–1931) and Otto Sackur[2] (1880–1914), who developed it independently as a solution of Boltzmann's gas statistics and entropy equations, at about the same time in 1912.

The Sackur–Tetrode formula is:

`S/(kN) = ln[ V/N ( (4pim)/(3h^2) U/N)^(3/2)] + 5/2`

where :

• V is the volume of the gas
• N is the number of particles in the gas
• U is the internal energy of the gas
• k is Boltzmann's constant
• m is the mass of a gas particle
• h is Planck's constant

Work and Energy Calculators

• Internal Energy of an Ideal Gas
• Internal Energy
• Change in Internal Energy
• Work
• R - Gas Constant
• Ideal Gas Law
• Sackur-Tetrode Equation
• First Law of Thermodynamics