Final answer:
To compute the voltage of the electrochemical cell at 25°C, one would typically use the Nernst equation along with the standard reduction potentials for the anode and cathode reactions. However, the lack of these potentials in the provided information makes it impossible to calculate the exact voltage for this specific cell.
Step-by-step explanation:
To compute the voltage at 25°C of an electrochemical cell consisting of pure cadmium immersed in a 4x10⁻³ M solution of Cd²⁺ ions and pure iron in a 0.7 M solution of Fe²⁺ ions, we use the Nernst equation. Given that we do not have the standard reduction potentials for these half-reactions, we cannot provide the exact voltage for this cell. However, if we had those standard reduction potentials, we would proceed as follows:
- Write the standard cell notation to identify the anode and cathode reactions.
- Use the standard reduction potentials to calculate the standard cell potential (E°cell).
- Apply the Nernst equation: Ecell = E°cell - ((RT)/(nF))ln(Q), where Q is the reaction quotient, R is the ideal gas constant (8.314 J/(mol·K)), T is the temperature in Kelvin, n is the number of moles of electrons transferred in the reaction, and F is the Faraday constant (96485 C/mol).
- Substitute the values for R, T, n, F, and the concentrations into the Nernst equation to find the cell potential (Ecell).
Without the standard reduction potentials for the half-reactions of Cd and Fe, we cannot calculate the exact voltage of this cell. We would need additional information such as the standard reduction potentials or data from a table of standard potentials to provide a complete answer.