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M-10
4.
Using the volumetric flasks provided, repeat steps 2, and 3 to prepare the remaining three
standard solutions. Follow the guide given below for the volume of stock solution to be
dispensed from the buret into the volumetric flask:
Standard Solution 2
approximately 10 mL, accurately measured
Standard Solution 3
approximately 5 mL, accurately measured
Standard Solution 4
approximately 3 mL, accurately measured
Remember to add the reagents outlined in step 3, in the order given, and allow the
solution to stand for 10 minutes BEFORE diluting with distilled water.
5.
Prepare a “blank” solution that contains
no
iron(II) standard by combining ONLY the
reagents outlined in step 3 in a volumetric flask, diluting to the mark and mixing well.
Part II:
Determination of the Wavelength of Maximum Absorbance
1.
Turn on the instrument by turning the power switch/zero control knob until the pilot light
is on and allow it to warm up for about 15 minutes. The instrument should be turned on
at the beginning of the laboratory period.
2.
Considering the following note, rinse one cuvette and fill it to the mark with the blank
solution.
NOTE:
Before filling the cuvette, always rinse it 3 times using about 1 mL of solution
per rinse). This prevents unwanted dilution of the solution.
Wipe the cuvette with a kimwipe to make sure that no fingerprints or particles are on the
glass. Check to make sure that no particles or air bubbles are present in the solution.
3.
Rinse the second cuvette of the matched set three times with 1 mL portions of the
standard solution #2 and then fill it to the mark. Wipe the cuvette dry.
4.
Determine the absorption spectra for the [Fe(Bipy)3]
2+
complex using standard
solution
#2
NOTE:
The spectrophotmeter must
be re-zeroed every time the wavelength is
changed.
