How many seconds does it take to deposit 81.5 g of Zn on a steel gate when 21.0 A is passed through a ZnSO4 solution?

Answer 1

It takes 96,485 coulombs to deposit 65.4g/2 = estimated 33 g Zn
You want 81.5 g so that will require how many coulombs?
That's 96,485 x (81.5/33) = ? C.
Then C = amperes x seconds.
You know C and amperes, solve for seconds. Remember that 33 g is an estimate so you need to use more accurate values.

Answer 2

kjbfdksajhf