Question

Calculate E∘cell for each of the following balanced redox reactions.

Part A: O₂(g)+2H₂O(l)+4Ag(s) → 4OH−(aq)+4Ag+(aq)
Part B: Br₂(l) + 2I−(aq) → 2Br−(aq) + I₂(s)
Part C: PbO₂(s)+4H+(aq)+Sn(s)→Pb₂+(aq)+2H₂O(l)+Sn₂+(aq)
Part D: Which of the reactions are spontaneous as written. Check all that apply
a. PbO₂(s)+4H+(aq)+Sn(s)→Pb₂+(aq)+H₂O(l)+Sn₂+(aq)
b. Br₂(l)+2I−(aq)→2Br−(aq)+I₂(s)
c. O₂(g)+2H₂O(l)+Ag(s)→4OH−(aq)+4Ag+(aq)

Answer 1

To calculate E°cell, standard reduction potentials are used from a table. The standard cell potential is the difference between the cathode and anode potentials. A positive E°cell value indicates a spontaneous reaction.

Step-by-step explanation:

To calculate E°cell for the given redox reactions, we need to determine the standard reduction potentials for the half-reactions involved. These can be found in a standard reduction potential table. The standard cell potential (°cell) is the difference between the reduction potentials of the cathode and anode (E° cathode - E° anode).

For Part A, we would look up the standard reduction potential for O₂(g) being reduced, and Ag⁰(s) being oxidized. Part B would involve the standard reduction potential for Br₂(l) being reduced and I⁻ being oxidized. In Part C, we would check values for PbO₂(s) reduction and Sn(s) oxidation.

To determine whether the reactions are spontaneous, we look at the sign of the °cell. If it is positive, the reaction is spontaneous under standard conditions. For Part D, this spontaneous nature can be verified through these calculations and using the concept that a positive cell potential indicates spontaneity.