I’m contacting you about the concentrations of the two copper (II) sulfate solutions that you were unable to correctly identify. The good news is that, for both samples, we were able to accurately determine their concentrations using Beer’s Law, a well-established law that governs the relationship between a solution’s concentration and the amount of wavelength the solution can absorb under standard conditions.
Before going any further, though, let me fill you in on some of procedures and methods that were followed during the process. A laboratory experiment was set up, using 5 samples of copper (II) sulfate solutions with concentration ranging from 0.080 to 0.4 mol/L. This was done in order to examine the relationship between the absorbance …show more content…
This was accomplished by using a blank sample, one that contained only distilled water. A cuvette containing the blank sample was placed in the spectrophotometer, which was used to calibrate the device. After the device was calibrated with the blank sample, a 0.4 Molar solution of copper (II) sulfate was then placed in the cuvette. Once the 0.4 molar solution was added, we determine the appropriate wavelength by identifying the highest peak from the graphs generated. After carefully examining the graph, we decided that the appropriate wavelength to use for studying copper (II) sulfate was 631.1 …show more content…
The absorption of unknown # 2 was a lot higher than that of the 0.4 molar standard solution, which was also an indication that the concentration of unknown #2 was much higher than that of the 0.4 standard solution. Since the absorption is directly proportional to the concentration of the solution, we decided to dilute the mixture in a 1:1 ratio with distilled water. The absorbance for the unknown was measured again and the results obtained were tabulated in table 02.
Graph 01, which can be found in the appendix, provides a more visual understanding of the direct relationship that concentration and absorption share. The slope of the graph, which came out as 2.981/M cm, measures the molar absorptivity of copper (II) sulfate at 631.1nm. The molar absorptivity is very important in this case, as it is intimately tied to the Beer’s Law equation.
Equipped with the knowledge of the appropriate wavelength, molar absorptivity, absorptions and known concentrations, we were able to make informed calculations and assumptions about the concentrations of the two unknown samples of copper (II) sulfate that were given to us. By
Before going any further, though, let me fill you in on some of procedures and methods that were followed during the process. A laboratory experiment was set up, using 5 samples of copper (II) sulfate solutions with concentration ranging from 0.080 to 0.4 mol/L. This was done in order to examine the relationship between the absorbance …show more content…
This was accomplished by using a blank sample, one that contained only distilled water. A cuvette containing the blank sample was placed in the spectrophotometer, which was used to calibrate the device. After the device was calibrated with the blank sample, a 0.4 Molar solution of copper (II) sulfate was then placed in the cuvette. Once the 0.4 molar solution was added, we determine the appropriate wavelength by identifying the highest peak from the graphs generated. After carefully examining the graph, we decided that the appropriate wavelength to use for studying copper (II) sulfate was 631.1 …show more content…
The absorption of unknown # 2 was a lot higher than that of the 0.4 molar standard solution, which was also an indication that the concentration of unknown #2 was much higher than that of the 0.4 standard solution. Since the absorption is directly proportional to the concentration of the solution, we decided to dilute the mixture in a 1:1 ratio with distilled water. The absorbance for the unknown was measured again and the results obtained were tabulated in table 02.
Graph 01, which can be found in the appendix, provides a more visual understanding of the direct relationship that concentration and absorption share. The slope of the graph, which came out as 2.981/M cm, measures the molar absorptivity of copper (II) sulfate at 631.1nm. The molar absorptivity is very important in this case, as it is intimately tied to the Beer’s Law equation.
Equipped with the knowledge of the appropriate wavelength, molar absorptivity, absorptions and known concentrations, we were able to make informed calculations and assumptions about the concentrations of the two unknown samples of copper (II) sulfate that were given to us. By