Question

We have seen that the voltage of a concentration cell can be affected by the concentrations of aqueous components and/or temperature. The identity of the redox pair also affects the observed voltage of a concentration cell in a somewhat subtle way. Carefully consider the Nernst equation. Rank the redox pairs below from greatest (1) to smallest (3) voltage in a concentration cell, assuming equal values of T and Q for all cells. Assume multimeter leads are connected to that measured voltages are positive.
a. Copper metal/copper(l) ion
b. Aluminum/aluminum ion
c. Magnesium metal/magnesium ion

Answer 1

Answer:

1) Magnesium metal/magnesium ion

2) Aluminum/aluminum ion

3)  Copper metal/copper(l) ion

Explanation:

The activity series is a series that shows the ease of reactivity of substances in an electrochemical cell.

The substances that are higher up in the series are more reactive in electrochemical cells.

Magnesium is the first element in the series that has the most negative redox potential  then followed aluminium.

Hence, according to Nernst,

1) Magnesium metal/magnesium ion

2) Aluminum/aluminum ion

3)  Copper metal/copper(l) ion