Gas Absorption and Water

As a rule of thumb, all gas-liquid absorption phenomena are exothermic (just think of the analogy with condensation, or the gas molecules losing kinetic energy).

The heat released is even greater if further chemical reactions occur, which is the case of NH3 getting hydrated and ionized (NH4+ OH-). BTW, ethanol is fairly soluble in water, so you can expect that it will be easily absorbed (It actually is).

So in an adiabatic absorption, the temperature of the mixture will increase. As the temperature increases absorption reduces.

That temperature increase is substantial? Can you approximately tell me the quantity of ammonia (20ºC) absorbed and temperature increase if we have one liter of water at 20ºC and atmospheric pressure?

Thanks

David

There are available, or used to be, tables similar to steam tables that present the type of information you are seeking to allow the calculation of these heat effects. I had the text a few years back. If I can find the reference I will post it.

Perhaps the following text would be of interest to you:

"Properties of Steam and Ammonia" by G. A. Goodenough, M.E., Prof. Thermodynamics Univ. of Illinois

(2nd Edition)

John Wiley and Sons, Inc.

New York (1917)

Thanks, I found it in the internet, good book, but I still have some uncertainties about absorption.

I would say it probably is as absorption of gassess increases with decreasing temperature therefore what this means is that the heat is on the product side of these reactions....so naturally heat should evolve rather then being used...

ethanol gas should be soluble in water