To determine the concentration of copper ions in a given water sample using polarography, you will need to follow these steps:1. Prepare the water sample: Filter the water sample to remove any suspended particles and then acidify it with a few drops of concentrated nitric acid HNO3 to prevent precipitation of metal hydroxides.2. Prepare the polarographic cell: Set up a polarographic cell with a dropping mercury electrode DME as the working electrode, a platinum wire as the auxiliary electrode, and a reference electrode e.g., Ag/AgCl or calomel electrode .3. Prepare the supporting electrolyte: Prepare a solution of a supporting electrolyte, such as 0.1 M KNO3 or NH4NO3, which will not interfere with the copper ion analysis.4. Add the water sample to the polarographic cell: Mix the water sample with the supporting electrolyte in the polarographic cell.5. Perform the polarographic analysis: Apply a potential sweep to the cell and record the current-potential curve polarogram . The potential at which the current starts to increase significantly corresponds to the reduction of Cu II to Cu I or Cu I to Cu 0 , depending on the copper species present in the sample.6. Calibration: Prepare a series of standard solutions containing known concentrations of copper ions and perform polarographic analysis on each of them. Plot the peak current or peak height as a function of the copper ion concentration to obtain a calibration curve.7. Determine the concentration of copper ions in the water sample: Measure the peak current or peak height for the water sample and use the calibration curve to determine the concentration of copper ions in the sample.Note that the exact procedure and parameters may vary depending on the specific polarographic instrument and method used. It is essential to follow the manufacturer's guidelines and consult relevant literature for optimal results.