One useful method for recycling scrap aluminum converts some of it to common alum [potassium aluminum sulfate dodecahydrate, KAl(SO4)212 H2O], an important dye fixative and food preservative.
(a) How many moles of potassium ions are in 392 g alum?
mol
(b) What is the mass % S in alum (to 3 significant figures)?
%
(c) What is the maximum amount of alum (in metric tons) that can be prepared from 11.2 metric tons of scrap aluminum (1 metric ton = 1000 kg)?