Colorimetry Flashcards
(2 cards)
What does colorimetry measure
Concentration of the solution
The amount of light that is transmitted/absorbed can be measured
Proportional to concentration of the solution
Describe the method to find concentration using a colorimeter
Choose suitable filter (complementary colour of the sample –> biggest readings as these wavelengths are being absorbed most strongly)
Zero colorimeter using pure solvent (usually water)
Make up series of standard solutions
Measure absorbance of each solution in colorimeter
Plot a calibration curve (absorbance against concentration)
Measure absorbance of unknown concentration –> use calibration curve to find concentration corresponding to that absorbance reading