To determine the concentration of copper ions in a sample using spectrophotometry, you can follow these steps:1. Prepare a series of standard solutions: First, you need to prepare a series of standard solutions with known concentrations of copper ions. You can do this by dissolving a known amount of copper salt e.g., copper sulfate in a known volume of distilled water. Prepare at least 5-6 standard solutions with varying concentrations, such as 1, 2, 5, 10, and 20 ppm parts per million .2. Select a suitable complexing agent: Copper ions in solution can form colored complexes with certain reagents, such as ammonia or ethylenediaminetetraacetic acid EDTA . These complexes have a characteristic absorption spectrum, which can be used to determine the concentration of copper ions. Choose a suitable complexing agent and add it to each of the standard solutions and the sample solution.3. Measure the absorbance of the standard solutions: Using a spectrophotometer, measure the absorbance of each standard solution at the wavelength corresponding to the maximum absorbance of the copper complex usually in the visible range, around 600-800 nm . Record the absorbance values.4. Plot a calibration curve: On a graph, plot the absorbance values of the standard solutions against their respective concentrations. Draw a best-fit line through the points, which represents the calibration curve.5. Measure the absorbance of the sample solution: Using the same spectrophotometer settings, measure the absorbance of the sample solution containing the copper ions and the complexing agent.6. Determine the concentration of copper ions in the sample: Locate the absorbance value of the sample solution on the y-axis of the calibration curve. Find the corresponding concentration on the x-axis. This value represents the concentration of copper ions in the sample solution.7. Calculate the concentration in the original sample: If you diluted the sample before analysis, multiply the concentration obtained in step 6 by the dilution factor to obtain the concentration of copper ions in the original sample.By following these steps, you can accurately determine the concentration of copper ions in a sample using spectrophotometry.