# Relationship between diffusion osmosis and entropy

### How does entropy relate to osmosis and diffusion? | Socratic

Diffusion is the spontaneous, net movement of particles from a region where they are in higher concentration to a region where they are in. Osmosis is the movement of water molecules across a Osmosis can also be explained via the notion of entropy, from statistical mechanics. survey conducted by the Association of American Medical Colleges, “transport processes”. (diffusion, osmosis, etc.) was identified as being the.

The osmotic pressure is equal to the force per unit area that is necessary to prevent passage of solvent into the region of greater solvent concentration. The osmotic pressure depends on the concentration of the solvent, not its identity. Basic explanation of osmosis Consider a permeable membrane with apertures small enough to allow water molecules, but not larger moleculesto pass through.

Suppose this semi-permeable selectively permeable membrane is in a volume of pure water, that is, separating two regions of pure water. At a molecular scale, every time a water molecule hits the membrane due to their natural kinetic energyit has a defined likelihood of passing through.

In this case, since the circumstances on both sides of the membrane are equivalent, there is no net flow of water through it. However, if there is a solution on one side of the semi-permeable membrane, that side will have fewer water molecules and thus fewer collisions with the membrane. This will result in a net flow of water to the side with the solution.

Assuming the membrane does not break, this net flow will slow and finally stop as the pressure on the solution side becomes such that the movement in each direction is equal. Whether that be due to a natural equilibrium or not, osmosis is inhibited by factors such as pressure potential or osmotic pressure. Osmosis can also be explained via the notion of entropy, from statistical mechanics.

### Can diffusion,osmosis be explained by second law of thermodynamics? - Physics Stack Exchange

As above, suppose a semi-permeable membrane separates equal amounts of pure solvent and a solution. Since a solution possesses more entropy than pure solvent, the second law of thermodynamics states that solvent molecules will flow into the solution until the entropy of the combined system is maximized.

Notice that, as this happens, the solvent loses entropy while the solution gains entropy. Equilibrium, hence maximum entropy, is achieved when the entropy gradient becomes zero. Examples of osmosis Many plant cells perform osmosis. The osmotic entry of water from outside the cell is opposed and eventually equaled by the pressure exerted by the cell wallcreating a steady state.

In fact, osmotic pressure is the main cause of support in plant leaves. In other words, the plant takes in the water so it can stay alive. The terms hypotonic, isotonic, or hypertonic reference the concentration of an external solution relative to the cell. If a plant cell or an animal cell is placed in a solution of sugar or salt: If the medium surrounding the cell has a higher water concentration than the cell less concentrated in terms of solutesthe cell will gain water through osmosis.

Such a solution is called a hypotonic solution.

## How does entropy relate to osmosis and diffusion?

If the medium has exactly the same water concentration, there will be no net movement of water across the cell membrane. Such a solution is called a isotonic solution. If the medium has a lower concentration of water than the cell, meaning that it is a more concentrated solution, the cell will lose water by osmosis. Such a solution is called a hypertonic solution.

When a plant cell is placed in a hypertonic solution, the water in the cell moves to an area higher in solute concentration, and the cell shrinks and so becomes flaccid pronounced flaxid. They know that molecules diffuse from areas of high concentration to areas of lower concentration, which is a different way of saying that molecules tend to distribute themsleves evenly in space. A specific example of this is osmosis, which is the diffusion of water molecules from regions of high water concentration to regions of lower water concentration.

This can be counterintuitive, expecially if ions move against their concentration gradient to equalize the charge gradient. For example, all plant cells are negatively charged inside. Positively charged ions enter if a channel protein in the membrane is open, even against the concentration gradient. There are many biological molecules that can gain electrons, becoming reduced, and lose electrons, becoming oxidized.

Reduced forms of these molecules have more energy than their oxidized forms, therefore reducing them requires a second event that supplies the energy. Absorption of a photon or oxidation of another molecule are required for these reduction reactions to proceed.

The two reactions must occur together.

### What is the relationship between osmosis, entropy and diffusion? | Yahoo Answers

Hydrolysis of ATP is necessary for many reactions to proceed, hence the continuous need for synthesis of ATP in living cells. Entropy and Free Energy. You are familiar with these concepts from General Chemistry.

Entropy is the disorder of a system. Free energy can quantify the potential work that a system can perform. They are related, allowing us to see that biological chemistry is the same as any other chemistry, just more complex. The 1st Law of Thermodynamics Several laws of thermodynamics have been developed. A basic knowledge of them is required to understand bioenergetics.

## What is the relationship between osmosis, entropy and diffusion?

The first law states that energy is never created or destroyed in any physical or chemical process but it may change forms. This is a useful fact when you are calculating energy flows. There is never a need to account for energy that disappears from the universe, for example. A point to make at this juncture is that when energy changes forms, e. In this case, some of the light energy is converted to heat and some is converted back into light fluorescence.