To quantify the amount of copper ions in a water sample using spectrophotometry, you can follow these steps:1. Prepare the sample: Collect the water sample and filter it if necessary to remove any suspended particles or debris.2. Complex formation: Add a suitable complexing agent to the water sample. A common complexing agent for copper ions is ammonium hydroxide, which forms a colored complex with copper ions. The reaction can be represented as: Cu + 4NH [Cu NH ] The [Cu NH ] complex has a characteristic blue color, which can be detected using spectrophotometry.3. Calibration curve: Prepare a series of standard solutions containing known concentrations of copper ions. Add the same complexing agent to these solutions as was added to the water sample. Measure the absorbance of each standard solution at the wavelength of maximum absorbance max for the copper-ammonia complex, which is typically around 625 nm. Plot the absorbance values against the known copper concentrations to create a calibration curve.4. Measure the sample absorbance: Measure the absorbance of the water sample at the same wavelength max used for the standard solutions.5. Determine the concentration: Use the calibration curve to determine the concentration of copper ions in the water sample based on its absorbance value. Locate the absorbance value of the sample on the y-axis of the calibration curve, and then find the corresponding concentration on the x-axis.6. Calculate the amount of copper ions: Multiply the concentration of copper ions by the volume of the water sample to obtain the total amount of copper ions in the sample.By following these steps, you can use spectrophotometry to quantify the amount of copper ions in a water sample.