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Calculate the corrosion current density of a copper metal in 1 M HCl solution at 25°C, given that the corrosion potential of copper electrode in the given environment is -0.35 V(SHE) and the exchange current density is 0.038 A/m². Also, determine the corrosion rate of copper in the same environment if the density of copper is 8.96 g

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To calculate the corrosion current density, we can use the Tafel equation, which relates the corrosion potential  E_corr  to the exchange current density  i_0  and the corrosion current density  i_corr . The Tafel equation is given by:E_corr = E_eq +  b/2  * ln i_corr / i_0 where E_eq is the equilibrium potential, b is the Tafel slope  usually assumed to be 120 mV/decade for the anodic and cathodic reactions , and ln is the natural logarithm. In this case, we are given E_corr  -0.35 V , i_0  0.038 A/m , and we can assume b = 120 mV/decade.First, we need to convert the Tafel slope to volts/decade:b = 120 mV/decade *  1 V / 1000 mV  = 0.120 V/decadeNow we can rearrange the Tafel equation to solve for i_corr:i_corr = i_0 * exp  E_corr - E_eq  * 2 / b Since we are not given the equilibrium potential  E_eq , we can assume that the corrosion potential is close to the equilibrium potential, which means that  E_corr - E_eq  is small. Therefore, we can approximate i_corr as:i_corr  i_0So, the corrosion current density is approximately:i_corr  0.038 A/mNext, we need to determine the corrosion rate of copper in the same environment. The corrosion rate  CR  can be calculated using Faraday's law:CR =  i_corr * M  /  n * F *  where M is the molar mass of copper  63.55 g/mol , n is the number of electrons involved in the corrosion reaction  for copper, n = 2 , F is Faraday's constant  96,485 C/mol , and  is the density of copper  8.96 g/cm .First, we need to convert the density of copper to g/m: = 8.96 g/cm *  1 m / 100 cm  = 8960 g/mNow we can calculate the corrosion rate:CR =  0.038 A/m * 63.55 g/mol  /  2 * 96,485 C/mol * 8960 g/m CR  6.97  10 m/yearSo, the corrosion rate of copper in 1 M HCl solution at 25C is approximately 6.97  10 m/year.

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