Calculation of solubility in water

[vinchem14]

Dear Forum members,

Situation: 3000 litre of water is pressurized with 1 bar helium gas in closed tank.

question 1: My question is that, if i know the solubility of helium gas in water at 1 bar partial pressure of helium over water at temp of 25 deg is 0.00145 g/litre, Whether i can apply this solubility law to entire bulk volume of water.

Solubility value for 3000 litre of water = 0.00145*3000 = ?

Whether solubility of helium gas depends upon the surface area of exposure of water or resistance offered by the liquid to transfer the solute from water interface to its bulk volume. or either i should interphase mass transfer theories to calculate the exact amount of soluble gases in 3000 litre of water.


question 2: If we have estimated the solubility in 3000 litres of water, how can we similarly estimate the degasification rate of solublized helium from water, if same water is kept under different conditions of nitrogen gas pressure or in a vacuum condition (after achieving sufficient solubility with helium gas). Is there any law to calculate the amount of solublized gas transfer from water to gas phase.

 

[Borek]

You can assume concentration of helium in the bulk is the one given if the system is left to equilibrate for long enough. With mixing 'long enough' means hours rather then days.

Speed of degasification is a completely different problem, one that is much more difficult to handle. Hopefully someone else will be able to help.