Chemicals
TopGeneral Information
Chrome alum is one of the possible combinations of alum. There is also potassium alum and ammonium alum. Chrome alum was formerly used in the leather tanning industry. It normally forms a dodecahydrate, but it can also form monohydrates (H2O), dihydrates (2H2O) and hexahydrates (6H2O).[1]
TopChemical & Physical Information
| Trivial name | Chrome alum |
| Chemical name | Chromium(III) potassium sulfate, dodecahydrate |
| Other names | Chroom aluin (NL,BE) |
| Type of chemical | Ionic compound (salt) |
| Chemical formula | KCr(SO4)2, 12H2O |
| CAS number | 10141-00-1 (anhydrous) 7788-99-0 (dodecahydrate) |
| Density | 1.83 g·cm-3 |
| Molar mass | 499.246 g·mol-1 |
| Melting point | 89 °C |
| Boiling point | ? |
| Soluble | In water |
| Solubility (water, 20 °C) | 240 g·L-1 (dodecahydrate) |
| Crystal system | Cubic |
| Appearance | Purple crystalline solid |
| Colour | Purple |
| Safety summary | Safe |
| Safety data | MSDS |
| Storage | Dry |
| Extra | - |
For more information, also look at the chrome alum crystals.
TopPhotos
(3 cm)
Sources
[1] Wikipedia
[2] Specimen from my personal collection, photo taken by me.
