Question What is the concentration of the analyte in each of

Question   “What is the concentration of the analyte in each of the 3 unknown solutions?”

Procedure “Make a set of dilute solutions from each unknown solution.  Measure the absorbance values of all the solutions, and graph them on a Beer’s Law plot.”

Data “Our experiment will provide us with the absorbance of the different solutions we make.” Explanation

“According to what we learned in this class, a Beer’s Law plot is utilized is to determine the unknown concentration of an analyte.

d. (4 pts) The TA identified that a ‘Beer’s Law plot cannot be generated for an unknown analyte.’   Review the steps needed to conduct a Beer’s Law experiment and consider the data graphed in a Beer’s Law plot (variables and units on each axis). Using chemical concepts, explain why this criticism is accurate. In your explanation, specifically indicate the key issue(s) that limits Beer’s Law from being applied to the three unknown solutions.

Solution

As absorbance is proportional to concentration by A=ecl where A is absorbance and c is concentration so absorbance versus concentration graph will a straight line plot so by measuring the absorbance of the unknown solutions and then comparing them with graph on concentration axis their concentrations could be known.

key issue that limits beers law from being applied to three unknown solutions is chemical factor that it shows deviation from the linearity and absorptivity cofficients at higher concentrations due to electrostatic interactions between molecules in close proximity.So concentrations should be known.