Hello everyone.  I am a scientist with background in biochemistry and PhD in protein engineering in the UK. 
I have done some bioreactor process development R&D in a small company and I attended a course in biochemical engineering in
Switzerland a number of years ago.  I am interested in chemical engineering.

Quote from: less_345 on Yesterday at 11:44:08 PM

subsystems have the same temperature (300 K), pressure (10e5 Pa), and volume (0.05 m3 each subsystem), but subsystem A has 1.5 mol of H2 and B 1 mol of He

You can't have two subsystems with the same PVT and different number of moles.

(Besides, neither 1 nor 1.5 moles fits given PVT data)

Thank you, in a previous step the wall changed from adiabatic to diathermic, thus the thermal equilibrium was reached, thus I made a mistake considering that the pressure will remain the same after that change as it was already in equilibrium, but I just realized that it was not the case…
In this case the change in volume will be due to the equilibrium in pressure, this change will produce a dS=0 since there is no change in heat/temperature and the process is reversible, am I right?

Good Afternoon Everyone

I'm a 3rd year chemical engineering student currently I have a problem in process design for ammonia stripping process I'm using crystallisation to crystallize  at this crystallisation process from some papers  the operation temperature is at the range of 50-140 degrees Celsius but in my case when I'll try to input the temperature 60degree Celsius the results became superheated does anyone can give me some insight why is this happened

Thank you so much for reading my post

I have a question with the following question:
1) Consider 1 system divided into two subsystems (A and B) separated by a diathermic, immobile, and impermeable wall, the subsystems have the same temperature (300 K), pressure (10e5 Pa), and volume (0.05 m3 each subsystem), but subsystem A has 1.5 mol of H2 and B 1 mol of He. If the wall becomes diathermic, flexible and impermeable, will there be a change in volume of the subsystems?

I'm not sure if the system will change to a new Teq due to the expansion of the subsystem with 1.5 mol of H2, or since the system is already in equilibrium, there will be no change of T nor of P, and thus, the volume will remain the same...

On the other hand, in case the volume is changed, should the change of entropy be calculated by the equation dS= n_ARln(V_2A/V_1A) + n_BRln(V_2B/V_1B)?

Worth to remember high titrant concentration means better detection of the endpoint, but worse accuracy (error reading burette for lower titrant volume means higher percent error).

Matter of finding a sweet spot, with good endpoint detection, but titrant volume around 80% of the burette volume.