Problem 13
For each of the following electrochemical cells, write equations for the oxidation and reduction half-reactions and for the overall reaction. (a) \(\mathrm{Pb}(\mathrm{s})\left|\mathrm{Pb}^{2+}(\mathrm{aq}) \| \mathrm{Sn}^{4+}(\mathrm{aq}), \mathrm{Sn}^{2+}(\mathrm{aq})\right| \mathrm{C}(\mathrm{s})\) (b) \(\mathrm{Hg}(\ell)\left|\mathrm{Hg}_{2} \mathrm{Cl}_{2}(\mathrm{s})\right| \mathrm{Cl}^{-}(\mathrm{aq}) \| \mathrm{Ag}^{+}(\mathrm{aq}) | \mathrm{Ag}(\mathrm{s})\)
Problem 14
Use cell notation to depict an electrochemical cell based upon the following reaction that is productfavored at equilibrium. \(\mathrm{Fe}^{3+}(\mathrm{aq})+\mathrm{Ag}(\mathrm{s})+\mathrm{Cl}^{-}(\mathrm{aq}) \rightarrow \mathrm{Fe}^{2+}(\mathrm{aq})+\mathrm{AgCl}(\mathrm{s})\)
Problem 15
What are the similarities and differences between dry cells, alkaline batteries, and Ni-cad batteries?
Problem 16
What reactions occur when a lead storage battery is recharged?
Problem 20
Balance each of the following unbalanced equations; then calculate the standard potential, \(E^{\circ}\) and decide whether each is product-favored at equilibrium as written. (All reactions are carried out in acid solution. (a) \(\mathrm{I}_{2}(\mathrm{s})+\mathrm{Br}^{-}(\mathrm{aq}) \rightarrow \mathrm{I}^{-}(\mathrm{aq})+\mathrm{Br}_{2}(\ell)\) (b) \(\mathrm{Fe}^{2+}(\mathrm{aq})+\mathrm{Cu}^{2+}(\mathrm{aq}) \rightarrow \mathrm{Cu}(\mathrm{s})+\mathrm{Fe}^{3+}(\mathrm{aq})\) (c) \(\mathrm{Fe}^{2+}(\mathrm{aq})+\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(\mathrm{aq}) \rightarrow\) \(\mathrm{Fe}^{3+}(\mathrm{aq})+\mathrm{Cr}^{3+}(\mathrm{aq})\) (d) \(\mathrm{MnO}_{4}-(\mathrm{aq})+\mathrm{HNO}_{2}(\mathrm{aq}) \rightarrow\) \(\mathrm{Mn}^{2+}(\mathrm{aq})+\mathrm{NO}_{3}^{-}(\mathrm{aq})\)
Problem 23
Which of the following elements is the best reducing agent under standard conditions? (a) Cu (b) Zn (c) Fe (d) \(\mathrm{Ag}\) (e) \(\mathrm{Cr}\)
Problem 24
From the following list, identify those elements that are easier to oxidize than \(\mathrm{H}_{2}(\mathrm{g})\) (a) Cu (b) Zn (c) Fe (d) \(\mathrm{Ag}\) (e) \(\mathrm{Cr}\)
Problem 32
One half-cell in a voltaic cell is constructed from a copper wire electrode in a \(4.8 \times 10^{-3} \mathrm{M}\) solution of \(\mathrm{Cu}\left(\mathrm{NO}_{3}\right)_{2}\). The other half-cell consists of a zinc electrode in a \(0.40 \mathrm{M}\) solution of \(\mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}\). Calculate the cell potential.
Problem 34
One half-cell in a voltaic cell is constructed from an iron electrode in an \(\mathrm{Fe}\left(\mathrm{NO}_{3}\right)_{2}\) solution of unknown concentration. The other half-cell is a standard hydrogen electrode. A potential of 0.49 V is measured for this cell. Use this information to calculate the concentration of \(\mathrm{Fe}^{2+}(\text { aq })\)
Problem 43
Which product, \(\mathrm{O}_{2}\) or \(\mathrm{F}_{2,}\) is more likely to form at the anode in the electrolysis of an aqueous solution of KF? Explain your reasoning.
