0 votes
55 views
ago in Analytical Chemistry by (350 points)
How can you determine the concentration of copper ions in a given sample of solution using spectrophotometry?

1 Answer

0 votes
ago by (570 points)
To determine the concentration of copper ions in a given sample of solution using spectrophotometry, you can follow these steps:1. Prepare a series of standard solutions: Create a series of standard solutions with known concentrations of copper ions. This can be done by dissolving a known amount of copper salt  e.g., copper sulfate  in a known volume of distilled water. Prepare at least five different concentrations to create a calibration curve.2. Measure the absorbance of the standard solutions: Using a spectrophotometer, measure the absorbance of each standard solution at the wavelength of maximum absorbance for copper ions  usually around 810 nm for Cu II  in aqueous solution . Make sure to zero the spectrophotometer using a blank solution  distilled water  before measuring the absorbance of each standard solution.3. Create a calibration curve: Plot the absorbance values of the standard solutions against their respective concentrations on a graph. The resulting graph should be a straight line, with absorbance on the y-axis and concentration on the x-axis. Calculate the equation of the line  y = mx + b , where m is the slope and b is the y-intercept.4. Measure the absorbance of the unknown sample: Using the same spectrophotometer settings, measure the absorbance of the unknown copper ion solution.5. Calculate the concentration of the unknown sample: Using the equation of the calibration curve, substitute the absorbance value of the unknown sample into the equation and solve for the concentration  x . This will give you the concentration of copper ions in the unknown sample.For example, if the equation of the calibration curve is y = 2x + 0.1, and the absorbance of the unknown sample is 0.5, then:0.5 = 2x + 0.10.4 = 2xx = 0.2The concentration of copper ions in the unknown sample is 0.2 M  or whatever unit you used for the standard solutions .
Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...