3 ms·
> No, not possible in the regular sense of the world. How do you know that?
by netr0ute 4y ago
> No, not possible in the regular sense of the world.
How do you know that?
- twawaaay 4y agoBecause osmotic pressure is a result of thermodynamics.
- wswope 4y agoEnthalpy of solution + first law of thermodynamics. Salt dissolved in water is in a very "stable", low-energy state, and getting it out necessarily requires a lot of energy input.
- klodolph 4y agoImagine two columns of water in a single U-shaped pipe, with a selectively permeable membrane at the bottom. One column contains salt water. The columns will have unequal levels, because of the osmotic pressure. If you had a different type of membrane that had a different pressure, you could swap it out and see the water level change. Repeatedly swapping the two membranes would allow you to pump water up the column, and you could siphon off this energy to create a perpetual motion machine, with some extra energy to spare.
- twawaaay 4y agoThanks. That's very good example I have not thought of.