Question #45009

A galvanic cell is constructed at $298 \text{ K}$ with the following cell representation:

$\ce{Sn(s) | Sn^{2+}(aq, 1.0 M) || Sn^{4+}(aq, 1.0 M), Sn^{2+}(aq, 1.0 M) | Pt(s)}$

The standard reduction potentials are $E^\circ_{\ce{Sn^{4+}/Sn^{2+}}} = 0.15 \text{ V}$ and $E^\circ_{\ce{Sn^{2+}/Sn}} = -0.14 \text{ V}$. Initially, the cell operates spontaneously. A ligand $\ce{L^-}$ is then added to the cathode compartment, which selectively forms the highly stable complex $\ce{[SnL_6]^{2-}}$ with $\ce{Sn^{4+}}$ (Formation constant $\beta_6 = 10^{22}$). The concentration of free $\ce{L^-}$ is maintained at $0.1 \text{ M}$, and the volume change is negligible.

What is the magnitude of the new cell potential, and what is the spontaneous cell reaction after the addition of the ligand? (Assume $\frac{2.303RT}{F} = 0.06 \text{ V}$)