To accurately determine the concentration of iron in a water sample using colorimetry, you can follow these steps:1. Collect a representative water sample: Ensure that the water sample is well-mixed and free from any debris or contaminants that may interfere with the colorimetric analysis.2. Prepare the reagents: You will need a colorimetric reagent that reacts specifically with iron to form a colored complex. A commonly used reagent for this purpose is 1,10-phenanthroline, which forms a red-orange complex with iron II ions.3. Convert iron III to iron II : If the water sample contains iron III ions, they must be reduced to iron II ions before reacting with the colorimetric reagent. This can be done by adding a reducing agent such as hydroxylamine hydrochloride to the water sample.4. Add the colorimetric reagent: Add a known amount of the 1,10-phenanthroline reagent to the water sample and mix well. The iron II ions will react with the reagent to form a colored complex.5. Allow the reaction to proceed: Wait for a sufficient amount of time usually 10-15 minutes for the reaction between iron and the reagent to reach completion.6. Measure the absorbance: Using a colorimeter or spectrophotometer, measure the absorbance of the colored complex at its maximum wavelength usually around 510 nm . The absorbance is directly proportional to the concentration of iron in the sample.7. Prepare a calibration curve: To determine the concentration of iron in the water sample, you will need to prepare a calibration curve using a series of standard iron solutions with known concentrations. Measure the absorbance of each standard solution and plot the absorbance values against the iron concentrations. The calibration curve should be linear, and its equation can be used to calculate the concentration of iron in the water sample.8. Calculate the iron concentration: Using the equation of the calibration curve, determine the concentration of iron in the water sample based on its absorbance value.As for the potential impact on human health, the World Health Organization WHO has set a guideline value of 0.3 mg/L milligrams per liter for iron in drinking water. Concentrations above this threshold can cause several issues:1. Aesthetic problems: High iron concentrations can cause an unpleasant metallic taste, staining of laundry and plumbing fixtures, and the growth of iron bacteria, which can produce a slimy, rust-colored deposit.2. Health effects: Although iron is an essential nutrient, excessive intake can lead to a condition called hemochromatosis, which causes the body to store too much iron. This can result in damage to organs such as the liver, heart, and pancreas, and increase the risk of conditions like diabetes, heart disease, and liver cancer.It is essential to monitor and control iron concentrations in drinking water to ensure that they remain within safe limits to protect human health and maintain water quality.