A galvanic cell consists of an electrode composed of nickel in a 1.0 M nickel(II) ion solution and another electrode composed of silver in a 1.0 M silver ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C. Standard reduction and oxidation potentials can be found here.
To calculate the standard potential for the galvanic cell, we need to find the reduction potentials for the half-reactions at the two electrodes and then subtract the reduction potential of the anode from that of the cathode.
1. The reduction half-reaction occurring at the nickel electrode is:
Ni2+(aq) + 2e- → Ni(s)
The standard reduction potential for this half-reaction can be found in a table of standard reduction potentials. According to the Nernst equation, at 25 °C, the reduction potential is 0.25 V.
2. The reduction half-reaction occurring at the silver electrode is:
Ag+(aq) + e- → Ag(s)
The standard reduction potential for this half-reaction is also found in a table of standard reduction potentials. At 25 °C, the reduction potential is 0.80 V.
3. To calculate the standard potential for the galvanic cell, subtract the reduction potential of the anode from that of the cathode:
Standard potential = (0.80 V) - (0.25 V) = 0.55 V
Therefore, the standard potential for this cell at 25 °C is 0.55 volts.
To calculate the standard potential for the galvanic cell, we need to find the reduction potentials for the half-reactions occurring at each electrode. The standard reduction potentials can be found in a table called the Standard Reduction Potential Table.
1. First, we identify the half-reactions occurring at each electrode:
- The nickel electrode: Ni^2+ + 2e^- -> Ni (reduction)
- The silver electrode: Ag^+ + e^- -> Ag (reduction)
2. Next, we look up the reduction potentials for each half-reaction in the Standard Reduction Potential Table. The reduction potentials are given with respect to the standard hydrogen electrode (SHE) as the reference electrode.
The reduction potential for the nickel half-reaction (Ni^2+ + 2e^- -> Ni) is given as -0.25 V.
The reduction potential for the silver half-reaction (Ag^+ + e^- -> Ag) is given as +0.80 V.
3. Now, we can calculate the standard potential (E°) for the cell by subtracting the reduction potential of the anode (nickel) half-reaction from the reduction potential of the cathode (silver) half-reaction:
E° (silver) - E° (nickel) = (+0.80 V) - (-0.25 V)
E° (silver) - E° (nickel) = 1.05 V
Therefore, the standard potential for this galvanic cell is 1.05 V at 25 °C.