Calculate the potential of the following two half-cells
that are connected by a salt bridge:
a galvanic cell consisting of a standard hydrogen
electrode on the left and a platinum electrode
immersed in a solution that is 3.50 3 1023 M in
TiO21, 0.07000 M in Ti31, and buffered to a pH
of 3.00.
To calculate the potential of the galvanic cell consisting of a standard hydrogen electrode and a platinum electrode immersed in a solution, we need to find the potential of each half-cell and then subtract them.
Here are the steps to calculate the potential:
1. Calculate the potential of the standard hydrogen electrode (SHE):
The standard hydrogen electrode is assigned a potential of 0.00 V. Since it is the reference electrode, its potential does not change.
2. Calculate the potential of the half-cell with the platinum electrode:
To determine the potential of the platinum electrode, we need to consider the redox reactions involving the species present in the solution.
a. Write down the balanced redox equation:
In this case, we have Ti3+ and TiO2+ as the species in the solution. The balanced redox equation is:
Ti3+ + e- → TiO2+
b. Look up the standard reduction potential (E°) for the above redox equation:
Use a reliable source or a table of standard reduction potentials to find the E° value for the Ti3+ and TiO2+ redox equation. Let's assume the E° value to be X.
c. Calculate the potential of the half-cell:
The potential of the platinum electrode half-cell is given by:
Potential = E° - (0.0591/n) * log([TiO2+]/[Ti3+])
- E° is the standard reduction potential we found in step 2b.
- [TiO2+] and [Ti3+] are the concentrations of TiO2+ and Ti3+ in the solution.
- n is the number of electrons involved in the redox reaction. In this case, it is 1.
3. Subtract the potential of the standard hydrogen electrode from the potential of the platinum electrode half-cell:
Potential of the galvanic cell = Potential of the platinum half-cell - Potential of the standard hydrogen electrode
By following these steps, you should be able to calculate the potential of the galvanic cell. Note that you will need the specific E° value for the Ti3+ and TiO2+ redox reaction to obtain the precise result.