What is the value for the e.m.f. of the cell represented by Pt(s)|OH-(aq)|O2(g)||Fe2+(aq)|Fe(s)?

What is the value for the e.m.f. of the cell represented by Pt(s)|OH-(aq)|O2(g)||Fe2+(aq)|Fe(s)?

• A. -0.44 V
• B. -0.84 V
• C. 0.40 V
• D. 0.84 V

Answer: (B)

To determine the value of the electromotive force (e.m.f.) of the electrochemical cell represented by the notation Pt(s)|OH–(aq)|O2(g)||Fe2+(aq)|Fe(s), it’s necessary to analyze the half-reactions occurring in the cell and their standard electrode potentials. In this cell, we have two half-reactions occurring at different electrodes: 1. The reduction half-reaction at the cathode involves the reduction of oxygen gas (O2) in the presence of hydroxide ions (OH–). The standard reduction potential for this half-reaction can be referenced from standard tables, which typically lists the standard reduction potential for O2 + 4e– + 2H2O → 4OH– is +0.40 V. 2. The oxidation half-reaction at the anode is the oxidation of ferrous ions (Fe2+) to solid iron (Fe). The standard oxidation potential for the ferrous ion is the negative of the standard reduction potential for Fe2+ + 2e– → Fe, which is commonly found to be about -0.44 V. Next, we calculate the standard cell potential (e.m.f.) using the standard reduction potentials of the two

To determine the value of the electromotive force (e.m.f.) of the electrochemical cell represented by the notation Pt(s)|OH–(aq)|O2(g)||Fe2+(aq)|Fe(s), it’s necessary to analyze the half-reactions occurring in the cell and their standard electrode potentials.

In this cell, we have two half-reactions occurring at different electrodes:

1. The reduction half-reaction at the cathode involves the reduction of oxygen gas (O2) in the presence of hydroxide ions (OH–). The standard reduction potential for this half-reaction can be referenced from standard tables, which typically lists the standard reduction potential for O2 + 4e– + 2H2O → 4OH– is +0.40 V.

2. The oxidation half-reaction at the anode is the oxidation of ferrous ions (Fe2+) to solid iron (Fe). The standard oxidation potential for the ferrous ion is the negative of the standard reduction potential for Fe2+ + 2e– → Fe, which is commonly found to be about -0.44 V.

Next, we calculate the standard cell potential (e.m.f.) using the standard reduction potentials of the two