Question
Electroplating is a widely used process. One of the most popular electroplating processes involves the plating of two metals, nickel and chromium, in separate vats. Nickel is plated first because it adheres better to iron, then the object is moved to a second vat where a layer of chromium is plated. The half-reactions occurring in each vat are shown below:
Plating of Nickel Ni2+(aq) + 2 e- „³ Ni(s)
Plating of Chromium Cr2O72-(aq) + 14 H+(aq) + 12 e- „³ 2 Cr(s) + 7 H2O(l)
1. 1. The power supply used in commercial electroplating provides each vat with approximately 1.50 x 103 A of current for 30.0 minutes. In which vat (Ni or Cr) is the greatest mass of metal deposited on a car bumper? Justify your answer.
2. 2. To save on production costs, most automobile bumpers are never coated with more than 200 g of chromium. Determine how much time a standard bumper should be immersed in a chromium vat.
I got number 1 i just need help with number 2 please and thank you
Plating of Nickel Ni2+(aq) + 2 e- „³ Ni(s)
Plating of Chromium Cr2O72-(aq) + 14 H+(aq) + 12 e- „³ 2 Cr(s) + 7 H2O(l)
1. 1. The power supply used in commercial electroplating provides each vat with approximately 1.50 x 103 A of current for 30.0 minutes. In which vat (Ni or Cr) is the greatest mass of metal deposited on a car bumper? Justify your answer.
2. 2. To save on production costs, most automobile bumpers are never coated with more than 200 g of chromium. Determine how much time a standard bumper should be immersed in a chromium vat.
I got number 1 i just need help with number 2 please and thank you
Answers
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)
96.485 x (200/8.67) = ? C
Then amperes x time = C
You know A and C, solve for time (in seconds)