Is Osmosis a Phenomenon of Thermodynamics?

[larsa]

I have read that osmosis " works like a machine ". It lifts weight ( this is obvious ) on the expense of thermal energy.

Does anyone has any thoughts about how it consumes thermal energy?
Thank you in advance.

 

[DrClaude]

I have read that osmosis " works like a machine ". It lifts weight ( this is obvious ) on the expense of thermal energy.

Could you give a reference for that?

Does anyone has any thoughts about how it consumes thermal energy?

I don't see how this can be correct. Osmosis is based on a difference of chemical potential, not temperature. I wouldn't know how to qualify the kind of energy it consumes, but it is not thermal, nor chemical (in the usual sense of that word).

 

[larsa]

Could you give a reference for that?I don't see how this can be correct. Osmosis is based on a difference of chemical potential, not temperature. I wouldn't know how to qualify the kind of energy it consumes, but it is not thermal, nor chemical (in the usual sense of that word).

Thanks for your answer. I don't remember the text where i met this expression but per example the hyperphysics article defines osmosis as a diffusion process driven by internal energy and internal energy is defined as energy associated with random motion of molecules.

That is something like thermal energy if i understand what i read.

 

[Kevin McHugh]

Osmosis is a pressure gradient, caused by chemical potential. Think potassium and sodium.

 

[larsa]

Osmosis is a pressure gradient, caused by chemical potential. Think potassium and sodium.

When you have time, could you explain what you mean?

 

[256bits]

I have read that osmosis " works like a machine ". It lifts weight ( this is obvious ) on the expense of thermal energy.

Does anyone has any thoughts about how it consumes thermal energy?
Thank you in advance.

I don't know what you mean by "consumes thermal energy."
But anyways, yes osmosis can be considered as being a phenomenom of thermodynamics.

If you take the ideal gas equation, PV=nRT, and arrange it just a bit, you get,
P=(n/V)RT

Replace P with π, and n/V and you get the osomotic pressure equation
π = cRT, where c is the concentration of the solute in moles per liter.

You can read some discussion here,
http://urila.tripod.com/osmotic.htm

 

[larsa]

I don't know what you mean by "consumes thermal energy."
But anyways, yes osmosis can be considered as being a phenomenom of thermodynamics.

If you take the ideal gas equation, PV=nRT, and arrange it just a bit, you get,
P=(n/V)RT

Replace P with π, and n/V and you get the osomotic pressure equation
π = cRT, where c is the concentration of the solute in moles per liter.

You can read some discussion here,
http://urila.tripod.com/osmotic.htm

Thank you for your answer and especially for the link