Problem: Consider a voltaic cell where the anode half-reaction is Zn(s)  →  Zn2+(aq) + 2 e- and the cathode half-reaction is Sn2+(aq) + 2 e–  →  Sn(s). What is the concentration of Sn2+ if Zn2+ is 2.5 X 10-3 M and the cell emf is 0.660 V? Use the reduction potentials in Appendix E that are reported to three significant figures. (a) 3.3 X 10-2 M(b) 1.9 X 10-4 M(c) 9.0 X 10-3 M(d) 6.9 X 10-4 M(e) 7.6 X 10-3 Marray{ { m Zn}^{+2}({ m aq})~+~2~{ m e}^-~& ightarrow &~ m Zn(s)~&~E^{circ}_{ m red}~&=&~-0.76~{ m V} cr { m Sn}^{2+}({ m aq})~+~2~{ m e}^–~& ightarrow &~ m Sn(s)~&~E^{circ}_{ m red}~&=&~-0.136~{ m V}}

FREE Expert Solution

Modified Nernst equation:

Ecell=E°cell-(0.0592n)log[anode][cathode]

↓ E° → oxidation → anode
↑ E° → reduction → cathode

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Problem Details

Consider a voltaic cell where the anode half-reaction is Zn(s)  →  Zn2+(aq) + 2 e- and the cathode half-reaction is Sn2+(aq) + 2 e  →  Sn(s). What is the concentration of Sn2+ if Zn2+ is 2.5 X 10-3 M and the cell emf is 0.660 V? Use the reduction potentials in Appendix E that are reported to three significant figures. 

(a) 3.3 X 10-2 M
(b) 1.9 X 10-4 M
(c) 9.0 X 10-3 M
(d) 6.9 X 10-4 M
(e) 7.6 X 10-3 M


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