Question

A concentration cell is made up of the Cu2+/Cu couple, where the Cu2+ concentrations are 1.0M and 0.10 M. It follows that the anode compartment contains the ________ which _______ in concentration as the cell operates, and the cathode compartment contains the ________ which _______ in concentration as the cell operates.
(a) 0.10 M Cu2+ solution, decreases; 1.0 M Cu2+ solution, also decreases
(b) 0.10 M Cu2+ solution, increases; 1.0 M Cu2+ solution, decreases
(c) 0.10 M Cu2+ solution, decreases; 1.0 M Cu2+ solution, increases
(d) 1.0 M Cu2+ solution, decreases; 0.10 M Cu2+ solution, increases
(e) 1.0 M Cu 2+ solution, increases; 0.10 M Cu2+ solution, decreases

Answer 1

answer: (b) 0.10 M Cu2+ solution, increases; 1.0 M Cu2+ solution, decreases

anode : oxidation takes place

Cu (s) ----------------> Cu+2 + 2e-

here concentration of Cu+2 increases.

concentration of Cu+2increases from 0.1M to 0.1 + (>0.1 M)

cathode : reduction takes place

Cu+2 (aq) + 2e- -----------------> Cu (s)

here concentration of Cu+2 decreases

concentration of Cu+2 decrease from 1M to < 1M

due to this tranfer of mass potential is generated .

representation for Concentration cell

Cu(s)/Cu+2(0.1) //Cu+2(1M)/Cu(s)