0
Many electrochemical reactions produce or consume species in the solution. The rates of reactions involving dissolved species which participate as reactants in the rate-determining step(that stage in the reaction which controls its rate) will be dependent on the concentration of the dissolved species. As the dissolved species are consumed by the reaction, so a greater change in potential will be required to maintain the current, and this is known as concentration polarization. A reaction for which concentration polarization dominates is referred to as mass-transport or diffusion controlled.
What else can I help you with?
What are the similarities between concentration polarization and kinetic polarization?
Concentration polarization is a condition in which the current in a electrochemical cell is limited by the rate at which reactants are brought to or removed from the surface of on or both electrodes. Kinetic is a condition which the current is limited by the rate at which electrons are transferred between the electrode surfaces and the reactant in solution. ref: fundamentals of analytical chemistry chapter 22.
What drives the diffusion of substances across a membrane?
The diffusion of substances across a membrane is driven by the concentration gradient, which is the difference in concentration of a substance on either side of the membrane. Substances naturally move from areas of high concentration to areas of low concentration in order to reach equilibrium.
Which involves a membrane - diffusion or osmosis?
Osmosis involves a membrane. It is the movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration. Diffusion, on the other hand, is the movement of particles from an area of high concentration to an area of low concentration, and it can occur with or without a membrane.
How does osmosis happen?
Diffusion of fluid through a semipermeable membrane from a solution with a low solute concentration to a solution with a higher solute concentration until there is an equal concentration of fluid on both sides of the membrane
How does osmosis occur across a semipermeable membrane?
Osmosis occurs across a semipermeable membrane when water molecules move from an area of higher concentration to an area of lower concentration, in order to balance the concentration of solutes on both sides of the membrane.
What is concentration polarization cross flow filtration?
Convective and back-diffusive flow of solvent can cause a build-up of dissolved solutes and macromolecules near and on the surface of the membrane this is known as concentration polarization. When concentration polarization occurs there is a differential solute concentration between the membrane surface and the bulk of the feed stream. The osmotic pressure in the polarized layer due to the high local solute concentration lowers the transmembrane pressure therefore decreasing flux. In cross -flow filtration there is a general decline in flux over time of operation this is due to concentration polarization. The decline in flux can be restored with the manipulation of the operating parameters.
What are the similarities between concentration polarization and kinetic polarization?
Concentration polarization is a condition in which the current in a electrochemical cell is limited by the rate at which reactants are brought to or removed from the surface of on or both electrodes. Kinetic is a condition which the current is limited by the rate at which electrons are transferred between the electrode surfaces and the reactant in solution. ref: fundamentals of analytical chemistry chapter 22.
What is the name of salt and sugar solution?
This is called concentration polarization.
How does nerve fiber become depolarized?
A nerve fiber becomes polarized when the resting potential of the membrane changes. It starts out with an unequal distribution of charges- the outside is more positive and the inside is less positive. (Sodium (Na+) is in a higher concentration on the outside of the membrane and Potassium (K+) is in a lower concentration on the inside of the membrane.) A stimulus changes the gradient- when more Na+ flows in, the resting potential changes and polarization occurs, allowing for an action potential to be propagated down the axon.
When was Journal of Membrane Science created?
Journal of Membrane Science was created in 1976.
Which term refers to the diffusion of water throughout a membrane?
Osmosis is the diffusion of water through a membrane (semipermeable) membrane. Water always moves from a high concentration of water to a low concentration of water.
What drives the diffusion of substances across a membrane?
The diffusion of substances across a membrane is driven by the concentration gradient, which is the difference in concentration of a substance on either side of the membrane. Substances naturally move from areas of high concentration to areas of low concentration in order to reach equilibrium.
Which involves a membrane - diffusion or osmosis?
Osmosis involves a membrane. It is the movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration. Diffusion, on the other hand, is the movement of particles from an area of high concentration to an area of low concentration, and it can occur with or without a membrane.
How does osmosis happen?
Diffusion of fluid through a semipermeable membrane from a solution with a low solute concentration to a solution with a higher solute concentration until there is an equal concentration of fluid on both sides of the membrane
How does osmosis occur across a semipermeable membrane?
Osmosis occurs across a semipermeable membrane when water molecules move from an area of higher concentration to an area of lower concentration, in order to balance the concentration of solutes on both sides of the membrane.
In the process known as osmosis what moves through a semipermeable membrane into an area of concentration?
In osmosis, water molecules move through a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration, in order to equalize the solute concentration on both sides of the membrane.
When one side of the membrane has a higher concentration of particles then the other side of the membrane what happens?
Particles will move from the side with higher concentration to the side with lower concentration until equilibrium is reached. This process is called diffusion and it helps to equalize the concentration of particles on both sides of the membrane.
