An unknown sample was prepared by placing a single analgesic tablet in a small beaker and adding 10 mL of methanol. After allowing the sample to dissolve, the contents of the beaker are quantitatively transferred to a 25 mL volumetric flask and diluted to volume with methanol. The sample is then filtered, and a 1.00 mL portion transferred to a 10 mL volumetric flask and diluted to volume with methanol. HPLC analysis gave a signal for caffeine of 21.47. Report the mg of caffeine in the tablet.

Island arcs island arcs are long, curved chains of oceanic islands associated with seismic activity and mountain-building processes at certain plate boundaries. they occur where oceanic tectonic plates collide. along one side of these island arcs, there is usually a long, narrow deep-sea trench. at island arcs, the denser plate is subducted and is forced into the partially molten mantle under the less dense plate. the islands are composed of the extrusive igneous rocks basalt and andesite. the basalt originates most likely from the plastic mantle. the andesite originates most likely from the melting of parts of the descending plate and sediments that had accumulated on its surface. which list identifies minerals present in andesite from the greatest percentage by volume to the least percentage by volume?