In a dry cell, MnO2 occurs in a semisolid electrolyte paste and is reduced at the cathode. The MnO2 used in dry cells can itself be produced by an electrochemical process of which one half-reaction is shown below.

Question

In a dry cell, MnO2 occurs in a semisolid electrolyte paste and is reduced at the cathode. The MnO2 used in dry cells can itself be produced by an electrochemical process of which one half-reaction is shown below.
Mn2+(aq) + 2 H2O(l)  MnO2(s) + 4 H+(aq) + 2 e -

If a current of 33.5 A is used, how many hours are needed to produce 1.60 kg of MnO2?

At which electrode is the MnO2 formed? 
cathode
anode

DrBob222 · Answer

96,485 coulombs will form approx 87/2 = approx 44 g MnO2. These are estimates and you need to redo them with more accurate numbers.
How many coulombs do you need to produce 1000 g? That's approx 96,485 x (44/1000) = ? = Q
Then Q = amperes x seconds. Substitute and solve for seconds and convert to hours.