To determine the concentration of copper ions in a water sample using colorimetric analysis, you will need to follow these steps:1. Collect a water sample from the specific location in the river.2. Prepare a series of copper standard solutions with known concentrations e.g., 0.1, 0.5, 1, 2, 5, and 10 ppm .3. Add a colorimetric reagent to each standard solution and the water sample. The reagent will react with the copper ions to form a colored complex. A common reagent for copper analysis is bicinchoninic acid BCA or bathocuproine.4. Allow the reaction to proceed for a specified time usually 5-15 minutes at room temperature or under controlled conditions, depending on the reagent used.5. Measure the absorbance of each standard solution and the water sample using a spectrophotometer at the appropriate wavelength e.g., 562 nm for BCA or 480 nm for bathocuproine .6. Plot a calibration curve by graphing the absorbance values of the standard solutions against their known copper concentrations.7. Determine the concentration of copper ions in the water sample by comparing its absorbance value to the calibration curve. Locate the absorbance value on the y-axis, then draw a horizontal line to intersect the calibration curve. From this intersection point, draw a vertical line down to the x-axis to find the corresponding copper concentration.8. Report the concentration of copper ions in the water sample, including the appropriate units e.g., ppm or mg/L .Keep in mind that the accuracy of the colorimetric analysis depends on the quality of the standard solutions, the reagent, and the spectrophotometer used. Additionally, other factors such as sample turbidity, pH, and the presence of interfering ions may affect the results.