First, we need to find the total current flowing through the steel pipe. We can do this by multiplying the corrosion current density by the surface area of the steel pipe.Total current I = Corrosion current density Surface areaI = 3.2 mA/cm 5 cmI = 16 mA 1 mA = 10^-3 A I = 16 10^-3 ANow, we need to find the total charge transferred per hour. We can do this by multiplying the total current by the time in seconds.Total charge Q = Total current TimeTime = 1 hour = 3600 secondsQ = 16 10^-3 A 3600 sQ = 57.6 C Coulombs Now, we need to find the weight loss of the steel pipe per year due to galvanic corrosion. To do this, we need to find the number of moles of iron Fe that have been corroded. We can use Faraday's law of electrolysis to find this.Faraday's constant F = 96485 C/mol Coulombs per mole of electrons Iron Fe has a valency of +2, so it requires 2 moles of electrons to corrode 1 mole of iron.Moles of electrons n = Total charge / Faraday's constantn = 57.6 C / 96485 C/moln = 5.97 10^-4 molMoles of iron Fe corroded = Moles of electrons / 2Moles of iron Fe corroded = 5.97 10^-4 mol / 2Moles of iron Fe corroded = 2.985 10^-4 molNow, we need to find the weight loss of the steel pipe. We can do this by multiplying the moles of iron corroded by the molar mass of iron.Molar mass of iron Fe = 55.85 g/molWeight loss per hour = Moles of iron Fe corroded Molar mass of iron Fe Weight loss per hour = 2.985 10^-4 mol 55.85 g/molWeight loss per hour = 0.0167 gNow, we need to find the weight loss per year.Weight loss per year = Weight loss per hour Hours in a yearHours in a year = 24 hours/day 365 days/year = 8760 hours/yearWeight loss per year = 0.0167 g/hour 8760 hours/yearWeight loss per year = 146.292 g/year