Page 45 - Practical book PC406-MNU-2025

MANSOURA NATIONAL UNIVERSIY
PHARM D- CLINICAL PHARMACY LEVEL II INSTRUNENTAL ANALYSIS (PC 406)

I-Colorimetric determination of KMnO4

 KMnO4 is widely used as a disinfectant in athlete’s foot and impetigo.

 It also used as an astringent to treat open and blistering wounds and infected eczema
 KMnO 4 has a violet color so, can be determined colorimetrically.

 Stock concentration of KMnO 4 solution

(standard solution) = 0.1 gm%

 Molecular weight of KMnO 4 = 158 gm.

1- Determination of max by drawing the absorption spectrum( in alkaline media):

Absorbance

max of KMnO4 = 520 nm

2-Drawing the standard calibration curve :

1) Transfer 2.0, 4.0, 6.0, 8.0, 10.0 ml of stock solution and 10.0 ml of unknown
sample solution into 100.0ml measuring flask (every student take only one volume

in his measuring flask)
2) Complete to the mark with water, shake well.
3) Measure the absorbance at 520 nm and draw the standard calibration curve
4) Measure (A) of unknown sample

5) Calculate the concentration of the unknown sample from previously plotted

calibration curve and calculate a, 1% , ε.
 cm 1

17 | P a g e S e c o n d s e m e s t e r 2 0 2 4 - 2 0 2 5