Question

Use the standard half-cell potentials listed below to calculate the standard cell potential for the following reaction occurring in an electrochemical cell at 25°C. (The equation is balanced.)

Pb(s) + Br2(l) → Pb2+(aq) + 2 Br⁻(aq) E° = ?
Pb²⁺(aq) + 2 e⁻ → Pb(s) E° = -0.13 V
Br₂(l) + 2 e⁻ → 2 Br⁻(aq) E° = +1.07 V

A) +1.20 V
B) +0.94 V
C) -0.94 V
D) -1.20 V
E) -0.60 V

Answer 1

To calculate the standard cell potential, we use Ecell = Ecathode - Eanode. However, additional information about the half-cell reactions is required to provide a complete answer, which is not given in the question.

Step-by-step explanation:

To calculate the standard cell potential for a given electrochemical reaction, we use the formula Ecell = Ecathode - Eanode. In this formula, Ecathode is the standard reduction potential for the half-reaction occurring at the cathode, and Eanode is the standard reduction potential for the half-reaction undergoing oxidation (written as a reduction) at the anode. It's essential to note that only the difference in potential can be measured, and all potentials are referenced to the standard hydrogen electrode (SHE) with a potential of 0 V.

However, the reaction at the anode is an oxidation, and hence its tabulated Eo value is reported as a reduction potential. Since the question does not provide specifics on the half-reactions involved and only gives a half-cell potential of -0.60 V, which is presumably for the cathode or anode, we cannot accurately calculate the standard cell potential without additional information on the counterpart half-cell. Normally, we would need both half-cell potentials to apply the provided formula correctly.