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 356 g alum? WebAssign will check your answer for the correct number of significant figures. 0.752 Correct: Your answer is correct. mol (b) What is the mass % S in alum (to 3 significant figures)? WebAssign will check your answer for the correct number of significant figures. 13.5 Correct: Your answer is correct. % (c) What is the maximum amount of alum (in metric tons) that can be prepared from 18.5 metric tons of scrap aluminum (1 metric ton = 1000 kg)? WebAssign will check your answer for the correct number of significant figures. metric tons