To determine the concentration of copper ions in a sample of water collected from a river using colorimetry, you would need to follow these steps:1. Collect a water sample from the river.2. Prepare a series of standard solutions with known concentrations of copper ions. This can be done by dissolving a known amount of copper sulfate in water and then diluting it to create different concentrations.3. Add a colorimetric reagent to each standard solution and the river water sample. A common reagent for copper ions is the bicinchoninic acid BCA reagent, which forms a colored complex with copper ions.4. Measure the absorbance of each standard solution and the river water sample using a colorimeter or spectrophotometer. The absorbance is directly proportional to the concentration of copper ions in the solution.5. Plot a calibration curve by graphing the absorbance values of the standard solutions against their known copper ion concentrations.6. Determine the concentration of copper ions in the river water sample by comparing its absorbance value to the calibration curve.Without the specific absorbance values and calibration curve, it is not possible to provide an exact concentration of copper ions in the river water sample. However, by following these steps, you can accurately determine the concentration using colorimetry.