Which of the following is NOT true about the blank for the experiment, 'Analysis of a Complex Iron Salt'?

A. The blank for this experiment must have 100 % transmittance if placed in a spectrometer (Spec 20).


B. A blank is composed of the solvent used to dissolve the analyte. For this experiment, the solvent is a combination of sulfuric acid, phosphoric acid, and water.


C. A blank is titrated to correct for any reactive impurities in the solvent. For this experiment, the impurities would be reducing agents that would react with KMnO4 (mimicking the behavior of C2O42鈥?).


D. The volume required to titrate the blank is subtracted from the volume used to titrate the analyte solution to give the ';corrected volume';.


E. All of these are true.





It's not D,E, and I don't think it's A, what is it?Which of the following is NOT true about the blank for the experiment, 'Analysis of a Complex Iron Salt'?
I would say A. The purpose of a blank is to get rid of any error, such as the impurity of the solvent, systematic errors, etc. However, a blank does not have to have 100% transmittance when placed in a Spec 20. However, the Spec 20 is adjusted to zero once the blank is in the instrument to zero out the errors which would be present in all of the samples.