What does an Oxygen concentration of 10-²⁴ bar mean?

What does an Oxygen concentration of 10-²⁴ bar mean?

The notation 10-²⁴ bar (or formulated 1.E-24)in connection with oxygen concentration refers to an extremely low partial pressure of oxygenin a given environment. Here’s a detailed explanation:

  1. Notion of oxygen partial pressure

The partial pressure of a gas in a mixture represents the pressure it would exert if it were alone in the same volume. It is often expressed in bar (or Pascals, 1 bar = 100,000 Pa).

By way of comparison, ambient air contains around 21% oxygen, and atmospheric pressure is around 1 bar. So, the partial pressure of oxygen in normal air is

1 x 0.21 = 0.21 bar

 

  1. Meaning of 10-²⁴ bar
  • A pressure of 10-²⁴ bar means an extremely low oxygen concentration.
  • To give an order of magnitude, this pressure is trillions of times lower than the partial pressure of oxygen in air.