Question

You have a stock 4.00 times 10^-4 solution of KMnO_4, and three 50.00ml volumetric flasks. Each contains 40.00ml, 20.00ml and 10.00ml of the stock solution, respectively. Each flask contains respectively. Each is diluted to the mark with water. After the solutions were well mixed, each was analyzed by the use of spectrophotometer using a 1.00-cm cuvette. The results are presented in the table below. Make a Beer's Law plot and determine the extinction coefficient (with units), as well as the concentration of two unknown solutions. In the right two columns (above), write-in the data you in the data you intend to plot. For unknown A Abs = 0.83, and for Unknown B Abs = 0.34

Answer 1

1.2 0.8 0.4 0.2 0.0001 0.0002 0.0003 0.0004 0.0005 Concentration

The relevent equation is y = 2637.5x + 0.022 where y = abs and x = conc.

unknown concentration A is = (0.83-0.022)/2637.5 = 3.06 *10^-4 M

unknown concentration B is = (0.34-0.022)/2637.5 = 1.21 *10^-4 M

Volumn, 하 Ab8 stoek ute 40 20 1O comen 1'o5 4X16 M 45 O 22 4 x 104 x 40 50 3.2 X10 M 24x 04x 10 50 Extinetion Coetticienmol Jen Pwte 4 0 26 1 0 O. 2625x104 o 2 212 5 x 104 2 28 125 x 109 o 215x10 1