It takes 96,485 coulombs to plate 1 equivalent Cr(52/6= about 8.67 g). To plate 200 g will require how many C? 96.485 x (200/8.67) = ? C Then amperes x time = C You know A and C, solve for time (in seconds)

where does the 6 come from?

Cr2O72-(aq) + 14 H+(aq) + 12 e- „³ 2 Cr(s) + 7 H2O(l)

It takes 12e for 2 Cr; therefore 6e for each Cr.