Chemical Forums
Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: billybob54 on February 17, 2009, 09:59:27 PM
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Suppose there was an equilibrium reaction A <-> B + C. Also, we have a semi-permeable membrane that allows B and C to pass through, but not A. We know that there is a certain amount of pressure required to separate B and C from A through this membrane. This pressure is called the osmotic pressure. Also, B and C release a certain amount of energy when they react. We will call this amount of energy E. I have a few questions about this.
1. Is the osmotic pressure at all related to the Energy released by B + C when they react? If so why/how?
2. If they are not related, is it possible that the Energy released by B + C reacting is greater than the energy required to create the osmotic pressure to force said B + C through the membrane to separate them from A?
If 2 is possible I have more questions to follow.
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Suppose there was an equilibrium reaction A <-> B + C. Also, we have a semi-permeable membrane that allows B and C to pass through, but not A. We know that there is a certain amount of pressure required to separate B and C from A through this membrane. This pressure is called the osmotic pressure. Also, B and C release a certain amount of energy when they react. We will call this amount of energy E. I have a few questions about this.
1. Is the osmotic pressure at all related to the Energy released by B + C when they react? If so why/how?
The osmotic pressure and the energy required to transport B and C across the membrane is solely related to the concentrations of B and C on either side of the membrane. (assuming B and C are uncharged. Things become more complicated if you have to take charge into account).
2. If they are not related, is it possible that the Energy released by B + C reacting is greater than the energy required to create the osmotic pressure to force said B + C through the membrane to separate them from A?
Sure. If the concentrations of B and C are equal on both sides of the membrane, no energy is required to transport the molecules across the barrier. Of course, the energy released by a reaction is primarily heat which is hard to harness in order to perform work.