Assume we have a balloon in a tank filled with a liquid , **without any gravitational** forces: **We just know the Temperature, V0 and V1**

![enter image description here][1]


I want to calculate the pressure exerted from the liquid on the balloon.  If it was just filled with gas I could easily calculate with PV=nRT, but this does not work for fluids.

Also by exclusion of gravity, the only source of pressure will be from the thermal energy ( fluid molecules moving and hitting on the balloon ) + internal cohesive energy.




UPDATE:

I think the only problem here is just finding the pressure exerted on the balloon by the liquid cohesive pressure ( in fact it is kind of **equation of state** problem ).  I studied a lot since I asked this question.  There are 2 pressures that I consider for using as P in this question:

1- Cohesive Energy density = 2.2973 GPa for water

2-Internal Cohesive Pressure= 168 MPa

My question is which one should be used here as P ?


  [1]: https://i.sstatic.net/0JLSJ.jpg