3. Iron(III) forms a complex with the thiocyanate having the formula Fe(SCN)2+. The complex has an absorption maximum at 580 nm. From the measured absorbances of the standard working solutions at that wavelength, the regression equation was obtained, y = 5810 x (in M) + 0.04812. A 0.550 g sample of a prenatal vitamin was ground and digested in the presence of dilute HCl. The digestate was transferred to a flask and brought up to the 50.0 mL mark with distilled water. A 250 L aliquot was taken from this solution and brought up to the 100.0 mL mark. This diluted solution gave an absorbance of 0.186.

to. (0.5 pts.) Select the analyte. i. Fe(SCN)2+

ii. Fe(III)

b. (0.5 pts.) Select the sample. i. Fe(SCN)2+

ii. Fe(III)

iii. thiocyanate

IV. prenatal vitamin

iii. thiocyanate

IV. prenatal vitamin

c. (1 pt.) Select the variable that represents the signal on the calibration curve:

i. the wavelength at which the analyte absorbs (580 nm)

ii. the absorbance

iii. sample volume

IV. the analyte concentration (CA)

d. (1 point) In the regression equation, y = 5810 x (in M) + 0.04812, which of the following figures of merit depends on the calibration slope?

i. accuracy iii. sensitivity ii. precision i. selectivity

and. (2 pts.) What fraction of light will be transmitted by the diluted solution?

F. (5 pts) How many mg of iron (MM 55.85) are in the prenatal vitamin?

g. (3 pts) What is the weight-for-weight percentage (%w/w) of iron in the prenatal vitamin?