Question

How many aluminium ions are needed to cross an ammeter if you want a current of 3A?

Probably has something to do with Q=IT??

Answer 1

Assuming that the time needed to cross the ammeter is 1 hour or 3600s, then using coloumb's law,
I x t = F x m / (eq. wt)

Using the given values and formula:
3 x 3600 = 96500 x m / (27/3)

Solving for m,
m = 1.007 g of Al3+