Adapting the Donnan Equation for 3 Diffusible Ions

Thread starter garytse86
Start date Nov 14, 2005
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Ions

In summary, the Donnan Equation is a mathematical formula used to describe the distribution of ions between two solutions separated by a semi-permeable membrane. It is important for studying ion diffusion because it allows for the prediction of the movement of multiple ions. To adapt it for three diffusible ions, an additional term called the "triple salt term" must be included. However, the Donnan Equation has limitations as it assumes the membrane is impermeable to all ions except for the diffusing ions. In practical applications, it can be used in various fields such as biology, chemistry, and environmental science to understand processes such as osmosis, ion exchange, and the transport of nutrients and waste products across cell membranes.

Nov 14, 2005

garytse86

How do you adapt the Donnan Equation to 3 difffusible ions?

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Nov 14, 2005

cronxeh

Gold Member

Use the Goldman Equation?

Nov 14, 2005

garytse86

I don't have the relative permeabilities.

Nov 14, 2005

garytse86

here is the Q, can't do the chloride part.

What is the Donnan Equation?

The Donnan Equation is a mathematical formula used to describe the distribution of ions between two solutions separated by a semi-permeable membrane.

Why is the Donnan Equation important for studying diffusion of ions?

The Donnan Equation allows us to predict the movement of multiple ions between two solutions, which is crucial for understanding diffusion and osmosis in biological systems.

How can the Donnan Equation be adapted for three diffusible ions?

In order to adapt the Donnan Equation for three ions, an additional term must be included to account for the charge of the third ion. This term is known as the "triple salt term" and it takes into account the interactions between all three ions.

What are the limitations of using the Donnan Equation for studying ion diffusion?

The Donnan Equation assumes that the membrane separating the two solutions is impermeable to all ions except for the diffusing ions. In reality, there may be other ions or molecules that can pass through the membrane, which can affect the accuracy of the predictions.

How can the Donnan Equation be used in practical applications?

The Donnan Equation has many practical applications in fields such as biology, chemistry, and environmental science. It can be used to understand processes such as osmosis, ion exchange, and the transport of nutrients and waste products across cell membranes.