Question: Quinine in a 1.664 g antimalarial tablet was dissolved in 0.10 M HCl to give 500 mL of solution. A 15.00 mL aliquot was then diluted to 100.0 mL with acid. The absorbance for the diluted sample at 247.5 nm provided a reading of 0.288 on an arbitrary scale. When measured under conditions identical to those for the diluted sample, a standard 100 ppm quinine solution registered 0.180. Calculate the mass in milligrams of quinine in the tablet.