What are concentration cells?

1 Answer
May 23, 2018

Answer:

A type of galvanic cell where the two half-cells are identical except for in concentration.

Explanation:

This is a concentration cell:

SparkNotes

As we can see, the two half-cells are completely identical—the two electrodes are both made of solid #Cu#, and the solutions both contain #CuSO_4#.

The only thing that's different in these half-cells is concentration of the #CuSO_4#—in one half cell, its concentration is #0.01M#, and in the other, its concentration is #1M#.

This will cause electrons to migrate in the direction that results in the increase in concentration of the #0.01M# #CuSO_4# cell and the decrease in concentration of the #1M# cell.

So, in our case, electrons will flow from left to right.
In the left half-cell, this causes #Cu(s)# to become #Cu^(2+)#, increasing its concentration.
In the right half-cell, #Cu^(2+)# ions reduce to become #Cu(s)#, decreasing its concentration.