"Published in Newark, California, USA"
A solution containing 4.48 ppm KMnO4 has a transmittance of 0.576 in a 1.00 cm cell at 520 nm. If the transmittance of an unknown solution is 0.735, what is the concentration of the unknown KMnO4 solution in ppm.
Solution:
The given word problem is about transmittance and absorbance problem in which we can get the concentration of any unknown solutions. Mostly, spectrophotometer is used in getting the concentration of unknown solutions including the blank sample and known sample. By Beer's Law, we can calculate the concentration of any unknown solutions as follows
where:
T = transmittance
A = absorbance
a = molar absorptivity
b = thickness of the cell
c = concentration of solution
If the transmittance of 4.48 ppm KMnO4 is 0.576, then the value of a which is the molar absorptivity is
If the value of transmittance for the unknown KMnO4 solution is 0.735, therefore, its concentration is
