posted by Alissa .
Im preparing my report for Synthesis of Alum chemistry lab. Need help with these 2 questions:
1-What other cations besides aluminum can be used to make alum crystals? Explain
2-Why we need to add sulfuric acid slowly to the solution as opposed to pouring it fast?
Chemistry Lab -
1. Which alum are you preparing? There are several. You can read about them here. https://en.wikipedia.org/wiki/Alum
Generally, a monovalent cation sulfate with a trivalent cation sulfate + 12 mols H2O of crystallization. K, Na, Al, Fe, Cr, etc. I don't know what you used.
2. H2SO4 added to water USUALLY (unless the H2SO4 is very weak) gets quite hot. I've seen it get so hot that the solution spatters; i.e., the solution boils at the point of impact.