Spectrophotometry is a technique used to measure the concentration of a specific compound in a sample by analyzing the amount of light absorbed by the compound at a particular wavelength. Here is a step-by-step explanation of the process:1. Prepare the sample: First, the sample must be prepared in a suitable solvent to create a homogeneous solution. The choice of solvent depends on the solubility and chemical properties of the compound of interest.2. Select the appropriate wavelength: Determine the wavelength at which the compound of interest absorbs light most strongly. This can be found using a reference material or by scanning the sample across a range of wavelengths and identifying the maximum absorbance.3. Prepare a calibration curve: Prepare a series of standard solutions with known concentrations of the compound of interest. Measure the absorbance of each standard solution at the selected wavelength using a spectrophotometer. Plot the absorbance values against the concentration of the standard solutions to create a calibration curve.4. Measure the absorbance of the sample: Measure the absorbance of the unknown sample at the selected wavelength using the spectrophotometer.5. Determine the concentration: Use the calibration curve to determine the concentration of the compound in the unknown sample. Locate the absorbance value of the sample on the y-axis of the calibration curve, and find the corresponding concentration on the x-axis.The Beer-Lambert Law is the equation involved in this process:A = l cWhere A is the absorbance, is the molar absorptivity a constant for a specific compound at a specific wavelength , l is the path length of the light through the sample usually 1 cm , and c is the concentration of the compound in the sample.Necessary equipment and materials:1. Spectrophotometer: An instrument that measures the absorbance of a sample at a specific wavelength.2. Cuvettes: Small, transparent containers used to hold the sample and standard solutions for measurement.3. Pipettes: Used to accurately transfer and measure the volume of solutions.4. Solvent: A liquid in which the compound of interest is dissolved.5. Standard solutions: Solutions with known concentrations of the compound of interest.Potential sources of error and mitigation:1. Impurities in the sample or solvent: Ensure that the sample and solvent are pure and free of contaminants that could interfere with the absorbance measurements.2. Instrumental error: Calibrate the spectrophotometer regularly and ensure that it is functioning correctly.3. Human error: Use proper pipetting techniques and ensure that the cuvettes are clean and free of scratches or fingerprints.Practical application:One real-world application of spectrophotometry is the determination of nitrate concentration in water samples. Nitrate is an important nutrient for plants, but excessive amounts can lead to water pollution and health problems. Spectrophotometry can be used to accurately measure nitrate concentrations in water samples, allowing for monitoring and management of water quality.