Question

A solution of KMnO4 has an absorbance of 0.539 when measured in the colorimeter. Determine the concentration of the KMnO4 given the following data for a calibration plot.
Concentration of KMNO4 (M) Absorbance
0.0150 0.081
0.0300 0.159
0.0450 0.260
0.0600 0.334

Answer 1

Answer:

Concentration of unknown solution is 0.0416 M

Explanation:

As we know  

Absorbance is equal to the product of molar absorptivity of KMnO4 m, path length and concentration

From the given set of graphical data, it is clear that the absorbance vs concentration is a straight line.  

From the graph, we can obtain-  

Y = 5.73 X – 0.0065

Absorbance = 0.232

0.232 = 5.73 X – 0.0065

X = 0.0416  

Concentration of unknown solution is 0.0416 M