A galvanic cell is assembled from a silver electrode in 0.0100 M AgNO (aq) (solution…
CHEMISTRY · Multi-part · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry
Problem
A galvanic cell is assembled from a silver electrode in 0.0100 M AgNO3(aq) (solution volume = 150 mL) and a lead electrode in 0.100 M Pb(NO3)2(aq) (solution volume = 250 mL). The initial mass of the silver electrode is 1.00 g, and the mass of the lead electrode is large enough that it will not be completely consumed during the experiment. After the switch is closed, the cell delivers a steady current of 1.20 A for 90.0 min before it is disconnected.
Atomic masses: Ag = 107.87 g mol−1; Pb = 207.2 g mol−1.
(a) Write the half-reactions that occur at the electrodes and the overall cell reaction.
(b) Calculate the total number of moles of electrons transferred during the 90.0 min interval.
(c) Using the initial amounts provided, determine quantitatively whether Ag+ ions in solution or metallic Ag in the electrode limits the operation of the cell during this interval, and justify your conclusion.
(d) Calculate the mass change of each electrode that actually occurs during the 90.0 min discharge.
(e) If the switch remained closed after 90.0 min with the same current, explain whether the cell could continue to operate and describe any observable changes that would occur at the silver electrode.