A student is given a standard galvanic cell, represented above, that has a Cu electrode and a Sn electrode. As current flows through the cell, the student determines that the Cu electrode increases in mass and the Sn electrode decreases in mass.
Identify the electrode at which oxidation is occurring. Explain your reasoning based on the student’s observations.
As the mass of the Sn electrode decreases, where does the mass go?
In the expanded view of the center portion of the salt bridge shown in the diagram below, draw and label a particle view of what occurs in the salt bridge as the cell begins to operate. Omit solvent molecules and use arrows to show the movement of particles.
A nonstandard cell is made by replacing the 1.0 M solutions of Cu(NO3)2 and Sn(NO3)2 in the standard cell with 0.50 M solutions of Cu(NO3)2 and Sn(NO3)2 . The volumes of solutions in the nonstandard cell are identical to those in the standard cell.
In another experiment, the student places a new Sn electrode into a fresh solution of 1.0 M Cu(NO3)2 .
Half-Reaction |
E ° (V) |
Cu+ + e− → Cu(s) |
0.52 |
Cu2+ + 2 e− → Cu(s) |
0.34 |
Sn4+ + 2 e− → Sn2+ |
0.15 |
Sn2+ + 2 e− → Sn(s) |
−0.14 |
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