Sciencemadness Discussion Board

Adsorption of gass - effects on volume and pressure

RogueRose - 5-12-2017 at 21:06

I'm trying to figure out how adsorption of a gas (N2) effects the volume of gas in a vessel filled with 13x sieves when using normal air at standard temp. The sieves will adsorb the N2 at about 22 PSI. I am wondering if the adsorption process packs the N2 molecules tighter together than in gaseous form, allowing for more volume of gas, at less relative pressure (due to the N2 adsorption to the sieves) - or if the volume remains the same.

If the tank/sieve setup allows for 1 mole of air to = 1 PSI, it would need 22 mole to reach the adsorption point. Then for each mole added (being roughly 78% N2), would the pressure in the vessel increase by ~22% - that which isn't adsorbed onto the sieves (& possibly a small percent for the N2 adsorption volume??) - so adding 4 mole would increase pressure to about 23 PSI.?

Also, is there any behaviour at the adsorption point of 22 PSI where additional pressure would trigger the adsorption, but the adsorption process would pack the N2 gas tighter, causing a drop in pressure - so it would be in a flux state?