Ferric alum, also known as ferric ammonium sulfate, is a chemical compound with the formula NH₄Fe(SO₄)₂·12H₂O. It is a kind of alum, a sulfate salt with a general formula of AB(SO₄)₂·12H₂O.
Ferric alum appears as weakly violet, octahedral crystals .
Here are some key points about ferric alum:
- Chemical composition: NH₄Fe(SO₄)₂·12H₂O
- Appearance: Weakly violet, octahedral crystals
- Solubility: Soluble in water
- Uses:
- Water treatment: Ferric alum is a common coagulant used in water treatment. It works by destabilizing suspended particles in water, allowing them to clump together and settle out.
- Dyeing: Ferric alum can be used as a mordant in dyeing. A mordant is a substance that helps a dye adhere to fabric.
- Laboratory applications: Ferric alum has a variety of laboratory applications, including use in histological staining and as an etching agent for printed circuit boards.
