Question

The volumes of a 1.10 ppm standard solution of Zn2+ shown in the table below were pipetted into separatory funnels each containing 5.00 mL of an unknown zinc solution. Each was extracted with three 5-mL aliquots of CCl4 containing an excess of 8-hydroxyquinoline. The extracts were then diluted to 25.0 mL, and their fluorescence measured with a fluorometer. The results were: Volume Std Zn2+, mL leter Reading 0.000 4.00 8.00 12.00 6.12 11.16 15.68 20.64 Calculate the concentration of zinc (in ppm) in the sample.

Answer 1

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Vs(ml) s 6.12 0 411.16 8 12 20.64 Vol of std Zn2+ vs Flurometer reading 15.68 25 y= 1.202x+ 6.188 20 15 10 5 0 14 12 10 4 2 0 Vs(mi)