Question

An electrochemical cell is a combination of two half cells consisting of a metal with its own ions in solution.

1. Represent the Daniell cell.

2. E°_cathode and E°_anode for the above cell are + 0.34 V and – 0.76 V respectively. Calculate the E°_cell ?

3. Give the graphical interpretation of the following graph.

Answer 1

1. Zn(s) | Zn²⁺ (aq) || Cu²⁺ (aq) | Cu(s)

2. E°_cell = E°_cathode – E°_anode = (-0.34V) – (-0.76V) = +1.1V

3. The graph indicates the variation of conductance with dilution for strong and weak electrolytes. For both of them Λ_m increases with dilution. For strong electrolytes like KCl, the graph is a straight line since the variation is linear. But for weak electrolytes like CH₃COOH the graph is a curve due to step increase in the value of molar conductance near infinite dilution.