Question

How the concentration polarization occurs in galvanic and electrolylic cells (in details)

mechanism of each cell

Answer 1

Polarization in cells occur when isolating barriers develop at the interface between the electrode and electrolyte. Electrolysis causes the elements in an electrolyte to be attracted towards one or the other pole.Concentration polarization is the uneven depletion of reagents in the electrolyte causes concentration gradients in boundary layers. The effect of concentration polarization are the isolation of electrode from electrolyte and the transfer of charges.The consequences of these isolation are same in both galvanic and elecctrolytic cells.

• The reduction potential decreases,the reduction rate slows and eventually stops.
• Electric current is increasingly converted into heat rather than into desired electrochemical work
• By ohm's law,either electromotive force decreases and current increases or vice versa
• The self discharge rate increases in the cells.

Concentration polarization is the part of polarization of an electrolytic cell resulting from changes in electrolyte concentration due to the passage of current through electrode or solution interface.

Concentration polarization in galvanic cells and its mechanism

A galvanic cell is an electrochemical cell that derives electrical energy from spontaneous redox reaction taking place within the cell.It consists of two different materials immersed in electrolytes,or individual half cells with different metals and their ions in solution connected by a salt bridge or seperated by a porous membrane.Oxidation takes place at anode and reduction takes place at cathode.concentration polarization occurs when redox reactions take place.

Concentration polarization in electrolytic cells and its mechanism

An electrolytic cell uses electrical energy to drive a non spontaneous redox reaction.An electrolytic cell is used to decompose chemical compounds in a process called electrolysis.An electrolytic cell has three important parts.Two electrodes,one anode and one cathode and an electrolyte.electrolyte is usually a solution of water or other solvents in which ions are dissolved.External voltage applied to electrode,ions are attracted to electrode with opposite charge. With an external potential of correct polarity and sufficient magnitude can electrolytic cell decompose a normal stable or inert compound in the solution.So here concentration polarization has an effect in its mechanism.