Fat Flat up or down

The friendliest place on the web for anyone that enjoys cooking.
If you have answers, please help by responding to the unanswered posts.
Your welcome Chris but I actually try to break things into steps. It makes learning much easier. Now for the second and final half or our lesson you need to understand Osmotic pressure.

Osmotic pressure

As mentioned before, osmosis can be opposed by increasing the pressure in the region of high solute concentration with respect to that in the low solute concentration region. The force per unit area required to prevent the passage of water through a semi-permeable membrane and into a solution of greater concentration is equivalent to the osmotic pressure of the solution, or turgor. Osmotic pressure is a colligative property, meaning that the property depends on the concentration of the solute but not on its identity.

Increasing the pressure increases the chemical potential of the system in proportion to the molar volume (δμ = δPV). Therefore, osmosis stops, when the increase in potential due to pressure equals the potential decrease from Equation 1, i.e.:

\delta PV = -RT \ln(1-x_2)\qquad (2)

Where δP is the osmotic pressure and V is the molar volume of the solvent.

For the case of very low solute concentrations, -ln(1-x2) ≈ x2 and Equation 2 can be rearranged into the following expression for osmotic pressure:

\delta P = RTx_2/V \qquad (3)

That completes our lesson in Osmosis 101. Simple Huh!
 
Kloset BBQR said:
Your welcome Chris but I actually try to break things into steps. It makes learning much easier. Now for the second and final half or our lesson you need to understand Osmotic pressure.

Osmotic pressure

As mentioned before, osmosis can be opposed by increasing the pressure in the region of high solute concentration with respect to that in the low solute concentration region. The force per unit area required to prevent the passage of water through a semi-permeable membrane and into a solution of greater concentration is equivalent to the osmotic pressure of the solution, or turgor. Osmotic pressure is a colligative property, meaning that the property depends on the concentration of the solute but not on its identity.

Increasing the pressure increases the chemical potential of the system in proportion to the molar volume (δμ = δPV). Therefore, osmosis stops, when the increase in potential due to pressure equals the potential decrease from Equation 1, i.e.:

\delta PV = -RT \ln(1-x_2)\qquad (2)

Where δP is the osmotic pressure and V is the molar volume of the solvent.

For the case of very low solute concentrations, -ln(1-x2) ≈ x2 and Equation 2 can be rearranged into the following expression for osmotic pressure:

\delta P = RTx_2/V \qquad (3)

That completes our lesson in Osmosis 101. Simple Huh!

HAMMOCK TIME! :grin:

Expanding Q!

Jack
 

Latest posts

Back
Top Bottom