Question

What is Loschmidt’s number? How is it related to Avogadro’s number?

Answer 1

1. Loschmidt’s number also called as Loschmidt’s constant, n₀ is the number of particles of an ideal gas in a given volume (m³). The  unit is m⁻³. At standard pressure (1 atm) and temperature (0 °C) the value of Loschmidt’s number is 2.686 x 10²⁵ m⁻³.

2. Loschmidt’s number,n₀ can be expressed as,
        n₀ =  $\frac{P}{kT}$
where P is the pressure of the gas, K is the Boltzmann constant and T is the thermodynamic temperature.

Since, k = R/NA (where R is the universal gas constant and NA is the Avogadro constant)
n₀ = $\frac{P}{(R/NA)T}$
n₀ = $\frac{PNA}{RT}$

Hence, n₀ α NA