To calculate the corrosion rate of iron in a 0.1M HCl solution, we need to determine the corrosion current density i_corr first, and then convert it to a corrosion rate. We will use the Tafel extrapolation method to determine the corrosion current density.The Tafel extrapolation method involves the anodic and cathodic Tafel slopes a and c and the corrosion potential E_corr . The anodic and cathodic reactions can be represented by the following Tafel equations:E = E_corr + a * log i / i_corr for the anodic reactionE = E_corr - c * log i / i_corr for the cathodic reactionGiven values:E_corr = -0.44 V vs. SHEa = 60 mV/dec 0.06 V/dec c = 120 mV/dec 0.12 V/dec Since we are dealing with a 0.1M HCl solution, the cathodic reaction is the reduction of hydrogen ions:2H + 2e HThe exchange current density i0 for this reaction can be calculated using the following equation:i0 = 10^ E_corr - E0 / a - c Where E0 is the standard potential for the hydrogen electrode, which is 0 V vs. SHE.i0 = 10^ -0.44 - 0 / 0.06 - -0.12 i0 = 10^-0.44 / 0.18 i0 = 10^-2.44 i0 3.63 x 10^-3 A/mNow we can determine the corrosion current density i_corr using the following equation:i_corr = i0 * 10^E_corr / a - 1 i_corr = 3.63 x 10^-3 * 10^-0.44 / 0.06 - 1 i_corr 3.63 x 10^-3 * 10^-7.33 - 1 i_corr 3.63 x 10^-3 * -0.999 i_corr 3.63 x 10^-6 A/mNow that we have the corrosion current density, we can calculate the corrosion rate CR using Faraday's law:CR = i_corr * M * n / F * Where:M = molar mass of iron 55.85 g/mol n = number of electrons involved in the reaction 2 for the reduction of hydrogen ions F = Faraday's constant 96,485 C/mol = density of iron 7.87 g/cm CR = 3.63 x 10^-6 * 55.85 * 2 / 96,485 * 7.87 CR 0.0000082 g/cm/yearThe corrosion rate of iron in a 0.1M HCl solution at 25C is approximately 0.0000082 g/cm/year.