Final answer:
To calculate the cell potential (Ecell) of an electrochemical cell at 298 K, we need to use the equation Ecell = Ecathode - Eanode. A) The cell with Mg/Mg²⁺ and Fe/Fe²⁺ electrodes has a cell potential of 1.93 V, with Mg/Mg²⁺ as the anode and Fe/Fe²⁺ as the cathode. B) The cell with AVAP³⁺ and Mg/Mg²⁺ electrodes cannot be calculated as the reduction potential of AVAP³⁺ is unknown. C) The cell with Al/Al³⁺ and Fe/Fe²⁺ electrodes has a cell potential of 1.22 V, with Al/Al³⁺ as the anode and Fe/Fe²⁺ as the cathode.
Step-by-step explanation:
To calculate the cell potential (Ecell) of an electrochemical cell at 298 K, we need to use the equation Ecell = Ecathode - Eanode. The cell potential is determined by subtracting the anode potential from the cathode potential.
A) A cell with Mg/Mg²⁺ and Fe/Fe²⁺ electrodes:
The standard reduction potentials for Mg²⁺ and Fe²⁺ are -2.37 V and -0.44 V, respectively. Since the standard cell potential is the difference between the reduction potentials, we have:
Ecell = (-0.44 V) - (-2.37 V) = 1.93 V
Mg/Mg²⁺ is the anode because it has the lower reduction potential, and Fe/Fe²⁺ is the cathode.
B) A cell with AVAP³⁺ and Mg/Mg²⁺ electrodes:
Unfortunately, AVAP³⁺ is not a known species, so we cannot determine its reduction potential and consequently the cell potential.
C) A cell with Al/Al³⁺ and Fe/Fe²⁺ electrodes:
The standard reduction potentials for Al³⁺ and Fe²⁺ are -1.66 V and -0.44 V, respectively. So we have:
Ecell = (-0.44 V) - (-1.66 V) = 1.22 V
Al/Al³⁺ is the anode because it has the lower reduction potential, and Fe/Fe²⁺ is the cathode.