Question

What are concentration cells? What is E^o in a concentration cell? What is the driving force for a concentration cell to produce a voltage? Is the higher or, the lower ion concentration solution present at the anode? When theanode ion concentration is decreased and/or the cathode ion concentration is increased, both give rise to larger cell potentials. Why?

Short answer

The cells which differ in the concentration of electrodes are called concentration cells. The ion concentration difference in two half cells is the driving force for a concentration cell to produce voltage. Lower ion concentration is present at the anode. If there is a decrease in anode concentration and an increase in cathode concentration, the value decreases $E_{cell}$. This is inversely related to the anode concentration because of its negative charge in the$E_{cell}$ formula.

Step-by-step solution

Definition of concentration cells

The cells which differ in the concentration of electrodes are called concentration cells. The current will pass through substance transportation with different concentrations from one cell to another.

Eo in a concentration cell

The concentration cell value can be zero due to their similar electrodes in two compartments. The production of concentration cell voltage by ion concentration difference in two half cells. There is a low concentration of ions at the anode.

Expression of concentration cell

The concentration cell expression can be denoted as:

$E_{cell}=-\frac{2.303RT}{nF}\log \left(\frac{\left[anode\right]}{\left[cathode\right]}\right)$

There is a decrease in anode concentration and an increase in cathode concentration which leads to a decrease in$E_{cell}$ value. This is inversely related to the anode concentration because of its negative charge in the$E_{cell}$ formula.