This is the boss. No calculator. $F = 96\,500\ \mathrm{C/mol}$, and every draw is pinned so the coulombs land on a clean fraction of a mole of electrons — 0.300, 0.600, numbers you can carry in your head from one line to the next. One rack, one shift, and every answer feeds the next: the cell's standard potential, then the charge the rectifier delivers, then moles of electrons, then moles of metal, then grams on the rack — and finally the only question the shop floor actually cares about, which is whether the order ships.

Two warnings, both earned. The first: a negative $E^{\circ}_{\text{cell}}$ is not an error here. It is the reason there is a rectifier on the bench at all — electroplating is a reaction that will not run by itself, so you pay it to. The second: a wrong $n$ never announces itself. It walks quietly to the last line and makes the mass wrong by a factor of two or three, with every step in between looking immaculate. Write each line down as you go.

Everything from the chapter rides in it. 5★ under par here is the chapter crown. Clock in.