To determine the concentration of the unknown copper II ion solution using polarography, we need to use the Ilkovic equation:i = n * D^2/3 * A^1/2 * C * v/RT ^1/6 where:i = current 2.5 mA n = number of electrons transferred in the redox reaction 2 for Cu2+ to Cu D = diffusion coefficient of the electroactive species we need to assume a value for this, let's say 7.2 x 10^-6 cm^2/s for Cu2+ A = area of the dropping mercury electrode DME we need to assume a value for this, let's say 0.03 cm^2 C = concentration of the electroactive species Cu2+ v = rate of mercury drop we need to assume a value for this, let's say 0.002 cm/s R = gas constant 8.314 J/mol*K T = temperature assuming room temperature, 298 K First, we need to convert the current from mA to A:i = 2.5 mA = 0.0025 ANow we can rearrange the Ilkovic equation to solve for the concentration C :C = i / n * D^2/3 * A^1/2 * v/RT ^1/6 Plugging in the values:C = 0.0025 / 2 * 7.2 x 10^-6 ^2/3 * 0.03 ^1/2 * 0.002/ 8.314*298 ^1/6 C 0.0025 / 2 * 0.000144 * 0.1732 * 0.036 C 0.0025 / 0.000002C 1.25 MThe concentration of the unknown copper II ion solution is approximately 1.25 M. Note that the actual concentration may vary depending on the actual values of the diffusion coefficient, electrode area, and drop rate, which were assumed in this calculation.