Search results
Results from the WOW.Com Content Network
Calcium sulfate (or calcium sulphate) is the inorganic compound with the formula CaSO 4 and related hydrates. In the form of γ- anhydrite (the anhydrous form), it is used as a desiccant . One particular hydrate is better known as plaster of Paris , and another occurs naturally as the mineral gypsum .
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO 4 ·2H 2 O. [4] It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk.
Bassanite is a calcium sulfate mineral with formula CaSO 4 · 1 / 2 H 2 O or 2CaSO 4 ·H 2 O. In other words it has half a water molecule per CaSO 4 unit, hence its synonym calcium sulfate hemihydrate. Bassanite was first described in 1910 for an occurrence on Mount Vesuvius. It was named for Italian paleontologist Francesco Bassani ...
Selenite, satin spar, desert rose, and gypsum flower are crystal habit varieties of the mineral gypsum.. All varieties of gypsum, including selenite and alabaster, are composed of calcium sulfate dihydrate (meaning that it has two molecules of water), with the chemical formula CaSO 4 ·2H 2 O. Selenite contains no selenium, the similar names both derive from Greek selḗnē (σελήνη 'Moon').
This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to around 200 °C (400 °F) under normal atmospheric conditions. [6] Anhydrite is commonly associated with calcite , halite , and sulfides such as galena , chalcopyrite , molybdenite , and pyrite in vein deposits.
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
Substance Formula 0 °C 10 °C 20 °C 30 °C 40 °C 50 °C 60 °C 70 °C 80 °C 90 °C 100 °C Barium acetate: Ba(C 2 H 3 O 2) 2: 58.8: 62: 72: 75: 78.5: 77: 75