Amagat

An amagat is a practical unit of number density. Although it can be applied to any substance at any conditions, it is defined as the number of ideal gas molecules per unit volume at 1 atm (= 101.325 kPa) and 0 °C (= 273.15 K).Citation
last = Hirschfelder
first = Joseph O.
author-link =
last2 = Curtiss
first2 = Charles F.
author2-link =
last3 = Bird
first3 = R. Byron
title = Molecular Theory of Gases and Liquids
publisher = John Wiley & Sons, Inc.
year = 1967
edition = Corrected printing
url =
doi =
id =
isbn = ] It is named after Emile Amagat, who also has Amagat's law named after him. The abbreviated form of amagat is "amg."

Definition

Number density in amg, denoted here by $eta$, is defined as:$eta=\; frac\{n\}\{n\_0\}$ ,

where "n"₀ = 1 amg = 2.686 7774e|25 m⁻³ = 44.614 981 mol/m³ is the Loschmidt constant.

In practice, number density in amagat of an ideal gas at pressure "P" and temperature "T" can be calculated as [In this formula, absolute units of pressure and temperature, relative to vacuum and absolute zero, must be used.] :$eta=\; left(frac\{p\}\{p\_0\}\; ight)left(frac\{T\_0\}\{T\}\; ight)$ ,where "T"₀ = 273.15 K and "p"₀ = 101.325 kPa.

Example

Number density of an ideal gas (such as air) at room temperature (20 °C) and 1 atm (101.325 kPa) is:$eta=\; left(frac\{1,\; atm\}\{p\_0\}\; ight)left(frac\{273.15\; K\}\{(273.15+20)\; K\}\; ight)=0.932\; \{\; m\; amg\}$.

References