# Sackur Tetrode Constant

Use Sackur Tetrode in Calcul.io. See what this built-in constant represents, enter it in an editable calculation, and review related values and units.

## sackurTetrode

Sackur-Tetrode constant at T=1 K and p=101.325 kPa

Try it yourself:

```calculio
sackurTetrode
```

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## Sackur–Tetrode constant in gas entropy

**sackurTetrode** is a constant used in the Sackur–Tetrode equation for the entropy of a classical monatomic ideal gas.

## Context

The equation combines volume, particle number, mass, and thermal energy with [boltzmann](https://calcul.io/constants/boltzmann/index.md) and [planckConstant](https://calcul.io/constants/planckConstant/index.md).

## Caveats

It assumes an ideal, dilute, classical monatomic gas; quantum degeneracy and interactions require other models. Use [log](https://calcul.io/function/log/index.md) only with dimensionless arguments after forming the correct expression.

[All constants](https://calcul.io/constants/index.md)