Explain why each of the redox systems below would NOT have standard cell potentials.a. A voltaic cell with Fe (s) and Fe3+ (0.75 M) in one half-cell, and Cr (s) and Cr3+ (1.0 M)in the other half-cell.b. A voltaic cell with Pb (s) and Pb2+ (1.0 M) in one half-cell, and a Pt electrode with H2 (g)at 1.10 atm and H+ at 1.0 M.
a. Fe^3+ was not 1.0Mb. The pressure of H2(g) was not at 1.0atm
a. This redox system would not have a standard cell potential because the two half-cells involve different metal ions and their corresponding ions in different concentrations. A redox reaction can only have a standard cell potential when both half-cells involve the same ions at standard concentrations. The Fe3+ and Cr3+ ions have different oxidation states, and therefore, the reduction potentials of each half-cell cannot be determined using standard reduction potentials.
b. This redox system would not have a standard cell potential because the half-cell involving H2 (g) and H+ ions does not involve a metal. A standard cell potential is only applicable to a redox reaction involving metal ions. The reduction potential of the Pt electrode cannot be determined using standard reduction potentials due to the involvement of H2 gas and H+ ions. Additionally, the hydrogen electrode in this redox system could not be used as a reference electrode since it is not a reversible electrode. A reference electrode must be a reversible electrode to provide a stable and reproducible standard potential.
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