Question

Consider a copper-zinc corrosion couple. If the current density at the copper cathode is 0.05 A/cm2, calculate the weight loss of zinc per hour if the copper cathode area is 100 cm2 and the zinc anode area is 1 cm2 . Group of answer choices 0.061 g/h 6.1 g/h 61 g/h

Answer 1

Answer: the weight loss of zinc per hour is 6.1 g/h

Option c) 6.1 g/h is the correct answer.

Step-by-step explanation:

Given that

copper cathode area is = 100 cm²

zinc anode area = 1 cm²

current density at the copper cathode = 0.05 A/cm²

The corrosion current can be converted to a rate of metal loss from its surface by using Faraday's law

W = ItM / nF

W is weight loss of metal , I is current ,

I = iCu × ACu = 0.05 A/cm² x 100 cm² = 5.0 A

M is atomic weight of metal

Atomic mass of Zn = 65.38 g/mol

n = number of electron

F = Faraday’s constant = 96,500 C/mol

so we substitute

W loss of Zn = (5 A) × (3600/h) (65.38 g/mol) / [2 × (96,500 C/mol) ]

= 1176840 / 193000

= 6.098 ≈ 6.1 g/h

Therefore the weight loss of zinc per hour is 6.1 g/h

Option c) 6.1 g/h is the correct answer.