what is the concentration of phosphate in the original lake water sample if the unknown lake water sample
To determine the concentration of phosphate in the original lake water sample, you need to follow a few steps.
1. Begin by measuring the concentration of phosphate in the unknown lake water sample. This can be done using a spectrophotometer, which measures the absorbance of a sample at a specific wavelength.
2. Prepare a series of standard solutions with known concentrations of phosphate. These solutions should cover a range of concentrations.
3. Measure the absorbance of each standard solution using the same spectrophotometer and at the same wavelength used for the unknown sample.
4. Plot a calibration curve using the absorbance values of the standard solutions on the x-axis and their corresponding known concentrations of phosphate on the y-axis.
5. Once you have the calibration curve, determine the concentration of phosphate in the unknown sample by finding its absorbance value on the x-axis and then drawing a vertical line until it intersects the calibration curve. From this intersection point, draw a horizontal line to the y-axis to read the corresponding concentration of phosphate.
6. The determined concentration of phosphate in the unknown lake water sample will be the concentration of phosphate in the original lake water sample.
Note: It's also important to perform multiple measurements and calculate the average for both the unknown sample and the standard solutions to ensure accuracy.