Chapter 19, Problem 8E

Given these half-cell reactions and associated standard reduction potentials, answer the questions that follow:

   $\begin{array}{c}{\left[\text{Zn}\left({\text{NH}}_{\text{3}}\right)\right]}^{2+}\left(\text{aq}\right)+2{\text{e}}^{-}\to \text{Zn}\left(\text{s}\right)+4{\text{NH}}_{\text{3}}\left(\text{aq}\right)\\ E^{°}=-1.015\text{V}\end{array}$

   $\begin{array}{c}{\text{Ti}}^{\text{3+}}\left(\text{aq}\right)+e^{-}\to T{i}^{2+}\left(aq\right)\\ E°=-0.37\text{V}\end{array}$

   $\begin{array}{c}{\text{VO}}^{\text{2+}}\left(\text{aq}\right){\text{+2H}}^{\text{+}}\left(\text{aq}\right){\text{+e}}^{\text{-}}\to {\text{V}}^{\text{3+}}\left(\text{aq}\right)\text{+}{\text{H}}_{\text{2}}\text{O}\left(\text{l}\right)\\ E°=0.340V\end{array}$

   ${\text{Sn}}^{\text{2+}}\left(\text{aq}\right)+2{\text{e}}^{\text{-}}\to \text{Sn}\left(\text{aq}\right)$

   $\begin{array}{l}\\ E°=-0.14V\end{array}$

a. Determine which pair of half-cell reactions leads to a cell reaction with largest positive cell potential, and calculate its value. Which couple is at the anode and which is at cathode?
b. Determine which pair of these half-cell reactions leads to the cell with the smallest positive cell potential, and calculate its value. Which couple is at the anode and which is at the cathode?