# Critical temperature for an ideal gas

What is the critical temperature for an ideal gas? It can't be found from Andrew's isotherm as it is for real gases and states critical temperature as $\frac{8a}{27 R \cdot b}$, but for ideal gases $a = b = 0$.

• The point is that ideal gasses don't have a critical temperature; by being composed of infinitesimal, completely non-interacting point particles, they are not subject to intermolecular interactions and phase changes. That's what makes them ideal, i.e. simple. – Nicolau Saker Neto Jul 22 '17 at 6:06
• Thus they cant be liquified? – user161158 Jul 22 '17 at 6:22
• Sure enough, they can't. – Ivan Neretin Jul 22 '17 at 6:28