Q. What is the chemical formula of alum?

Answer

Ferric alum is also known as ammonium ferric sulfate due to its composition and it mainly consists of violet crystals that can be dissolved completely in water making a solution that is light orange with a brown shade of color. If the ferric alum crystals are too large then when they are mixed in water, they should be left overnight under constant magnetic stirring. Based on its composition, the chemical formula of ferric alum is NH₄Fe(SO₄)₂.