You measure the absorbance of each solution (at λmax = 524 nm) and obtain the following results:

Solution Absorbance

Stock solution 3.04

Solution #1 0.494

Solution #2 0.338

Molarities

Stock: 8.1*10-5M

Solution 1: 1.338*10-5M

Solution 2: 9.198*10-6M

Determine the concentration of the unknown solution in terms of molarity.

The concentration is equal to 1.88x10^-5 M

Explanation:

To calculate the concentration of the unknown solution of 0.699 of absorbance, we must make a graph in Excel and obtain the equation that represents the absorbance vs. molar concentration.

graphing the concentration on the "x" axis and the "y" axis of the absorbance and also linearizing, we have the following expression:

y = 37640x - 0.0089

Clearing x, we have:

x = (y + 0.089) / 37640 = (0.699 + 0.089) / 37640 = 1.88x10^-5 M