Water Potential: Kinetic or Potential Energy?

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SUMMARY

Water potential is defined as the chemical potential of water in a system, particularly in solutions, and is not strictly categorized as kinetic or potential energy. It is mathematically represented by the equation \(\mu_{water} = \left( \frac {\partial G}{\partial n_{water}} \right) _{S,V,n_{others}}\), where \(G\) is Gibbs Free Energy. The concept of water potential is crucial in understanding osmotic gradients, as water moves towards areas of lower water potential. Additionally, water potential can be described in terms of Gibbs free energy, indicating that it is a measure of the free energy available in a solution.

PREREQUISITES
  • Understanding of Gibbs Free Energy and its implications in chemical systems
  • Familiarity with the concept of chemical potential in solutions
  • Knowledge of osmotic gradients and their biological significance
  • Basic physics concepts related to energy forms, including kinetic and potential energy
NEXT STEPS
  • Research the relationship between water potential and osmotic pressure in biological systems
  • Explore the mathematical derivation of Gibbs Free Energy and its applications in thermodynamics
  • Investigate the role of water potential in plant physiology and nutrient uptake
  • Learn about the sodium/potassium pump and its relation to osmotic potential in neuronal activity
USEFUL FOR

Biologists, chemists, and students studying plant physiology or cellular biology, particularly those interested in osmotic processes and energy dynamics in solutions.

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Is water potential the kinetic energy or potential energy of water? Coz my textbook says it potential energy whereas another reference book says ts kietic energy
 
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Excuse me, is this a technical term in biology? Because normally the word potential, used by itself, means potential energy. The potential energy DIFFERENCE between a particle of water at two different heights is the mass of the particle times the height difference. If the particle then FALLS from the heigher height to the lower one, the kinetic energy (energy of motion) that it has gained at the bottom of the fall will equal the potential energy that it has lost; \frac{1}{2}mv^2 = md.
 
selfAdjoint said:
Excuse me, is this a technical term in biology? Because normally the word potential, used by itself, means potential energy. The potential energy DIFFERENCE between a particle of water at two different heights is the mass of the particle times the height difference. If the particle then FALLS from the heigher height to the lower one, the kinetic energy (energy of motion) that it has gained at the bottom of the fall will equal the potential energy that it has lost; \frac{1}{2}mv^2 = md.

Very cool selfAdjoint!:-p

How about the potential water offers for the development of life? Is there a physics formula for that??

It must have to do with the bond and the simple molecular structure of the H20.

Another thing about water I've heard is that it mimics the configuration of any other chemical or solution that enters it. I was told this as an explanation for the mechanism of dissolution or dilution. This would present another potential water holds... in the common use of the word "potential".

Potentially, water (under high pressure) can and is used as a laser to cut stone, wood and even metal. Probably an Egyptian invention:wink: .

Here's a page on "Standard metal cutting processes: laser cutting vs. water jet cutting"

http://www.teskolaser.com/waterjet_cutting.html
 
Last edited:
Water potential (\Psi) is used to describe the osmotic gradient, that fact that water will always move to an area of lower water potential. Water potential can be described in terms of Gibbs free energy;

\Psi = \frac{G}{V}

Where V is the molar volume of water. Water potential is a measure of the free energy in a solution. The lower the water potential the less free energy there is in the system the more potential energy there is. Therefore, water potential can be said to me a measure of potential energy.

~H
 
"Water potential" is nothing but the chemical potential of water in any system where water is a component (eg: in a solution).

\mu_{water} = \left( \frac {\partial G}{\partial n_{water}} \right) _{S,V,n_{others}}

Naturally, since G, the Gibb's Free Energy (or U, H or F, which can also be used in a definition like the one above) is intensive, the "water potential" of pure water (or pure anything else) under standard conditions is 0.

The water potential (or any chemical potential) is not an energy at all, though in some cases it is looks like one. When it does, it seems to resemble a potential energy. This is not, however, to say that it is independent of the KE of particles in the system. It isn't, as is evident if you write the definition in terms of the Helmholtz Free Energy, F(T,V,{n}).

For an equeous solution, the water potential is given by (if you're not too picky about accuracy) the slope of the graph of standard enthalpy of dilution as a function of the mole fraction of water (though usually, the graph is drawn with respect to the mole fraction of the solute).
 
Gokul43201 said:
"Water potential" is nothing but the chemical potential of water in any system where water is a component (eg: in a solution).

\mu_{water} = \left( \frac {\partial G}{\partial n_{water}} \right) _{S,V,n_{others}}

Naturally, since G, the Gibb's Free Energy (or U, H or F, which can also be used in a definition like the one above) is intensive, the "water potential" of pure water (or pure anything else) under standard conditions is 0.

The water potential (or any chemical potential) is not an energy at all, though in some cases it is looks like one. When it does, it seems to resemble a potential energy. This is not, however, to say that it is independent of the KE of particles in the system. It isn't, as is evident if you write the definition in terms of the Helmholtz Free Energy, F(T,V,{n}).

For an equeous solution, the water potential is given by (if you're not too picky about accuracy) the slope of the graph of standard enthalpy of dilution as a function of the mole fraction of water (though usually, the graph is drawn with respect to the mole fraction of the solute).

I stand corrected.

~H
 
Gokul43201 said:
"Water potential" is nothing but the chemical potential of water in any system where water is a component (eg: in a solution).

\mu_{water} = \left( \frac {\partial G}{\partial n_{water}} \right) _{S,V,n_{others}}

Naturally, since G, the Gibb's Free Energy (or U, H or F, which can also be used in a definition like the one above) is intensive, the "water potential" of pure water (or pure anything else) under standard conditions is 0.

The water potential (or any chemical potential) is not an energy at all, though in some cases it is looks like one. When it does, it seems to resemble a potential energy. This is not, however, to say that it is independent of the KE of particles in the system. It isn't, as is evident if you write the definition in terms of the Helmholtz Free Energy, F(T,V,{n}).

For an equeous solution, the water potential is given by (if you're not too picky about accuracy) the slope of the graph of standard enthalpy of dilution as a function of the mole fraction of water (though usually, the graph is drawn with respect to the mole fraction of the solute).


Yo! Heavy duty physics dudes!

Is there a similar equation for Sodium potential or Potassium potential... in reference to the sodium/potassium osmotic "pump" or the osmotic pressure created along a neuron's axon (resulting in em activity)?
 

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