Calculate the equilibrium constant for the reaction between Ni2+(...

Question

Calculate the equilibrium constant for the reaction between Ni2+(aq) and Cd(s) at 25 °C.

Accepted Answer

Identify the half-reactions involved in the redox process. For the reaction between $$Ni^{2+}(aq) $$and Cd(s), the half-reactions are: $$Ni^{2+}(aq) + 2e$$^- \rightarrow Ni(s) and Cd(s) \rightarrow $$Cd^{2+}(aq) + 2e^-.. $$Look up the standard reduction potentials (E^\circ) for each half-reaction from a standard reduction potential table. The standard reduction potential for $$Ni^{2+}/Ni is $$typically around -0.25 V, and for $$Cd^{2+}/Cd$$, it is around -0.40 V.. Calculate the standard cell potential (E_{cell}^\circ) for the overall reaction by subtracting the anode potential from the cathode potential: E_{cell}^\circ = E_{cathode}^\circ - E_{anode}^\circ.. Use the Nernst equation to relate the standard cell potential to the equilibrium constant (K). The equation is: E_{cell}^\circ = \frac{RT}{nF} \ln K, where R is the gas constant, T is the temperature in Kelvin, n is the number of moles of electrons transferred, and F is Faraday's constant.. Rearrange the Nernst equation to solve for the equilibrium constant (K): K = $$e^{\frac{nFE_{cell}$$^\circ}{RT}}. Substitute the known values (R, T, n, F, and E_{cell}^\circ) to find K.

Calculate the equilibrium constant for the reaction between Ni2+(aq) and Cd(s) at 25 °C.

Key Concepts

Equilibrium Constant (K)

Nernst Equation

Standard Electrode Potentials