Determine the cell potential (in V) for a platinum electrode in an acidic solution of 0.004M H+(aq), 3.226M ClO4-(aq) and 4.445M ClO3- (aq) ions, coupled to a gold electrode in 3.238 M Au3+ (aq) at 307.10 K.
Im confused about the mulitple molarities given for the platinum electrode. Do i just mutiply them in the Ecell equation?
To calculate the cell potential (Ecell) for the given electrochemical cell, you need to use the Nernst equation, which takes into account the concentrations of the species involved.
The Nernst equation is given as: Ecell = E°cell - (RT/nF) * ln(Q)
Where:
- Ecell is the cell potential
- E°cell is the standard cell potential (obtained from tables)
- R is the ideal gas constant (8.314 J/(mol·K))
- T is the temperature in Kelvin (307.10 K)
- n is the number of moles of electrons transferred per mole of reactant
- F is Faraday's constant (96485 C/mol)
- Q is the reaction quotient, calculated using the concentrations of the species involved
In this case, you have a platinum electrode in an acidic solution. The half-reaction occurring at the platinum electrode is the reduction of H+ ions to H2. The half-reaction occurring at the gold electrode is the reduction of Au3+ ions to Au.
Given that the reactants are in their standard states, the standard cell potential is equal to the difference in standard reduction potentials between the two half-reactions.
However, to calculate the cell potential at non-standard conditions, you need to consider the concentrations of the species involved. In this case, the concentrations given are for the acidic solution.
To calculate the reaction quotient Q, you will use the concentrations of the species involved in the reduction half-reactions at the platinum and gold electrodes. The equation for Q is as follows:
Q = ([H2]/[H+]) * [Au]/[Au3+]
Where:
- [H2] is the concentration of H2 (unknown)
- [H+] is the concentration of H+ ions (0.004 M)
- [Au] is the concentration of Au (unknown)
- [Au3+] is the concentration of Au3+ ions (3.238 M)
You need to solve for [H2] and [Au] to calculate Q and then substitute it into the Nernst equation along with the other given values to calculate the cell potential (Ecell) at the given conditions.