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Aluminium sulfate is rarely, if ever, encountered as the anhydrous salt. It forms a number of different hydrates, of which the hexadecahydrate Al 2 (SO 4) 3 ·16H 2 O and octadecahydrate Al 2 (SO 4) 3 ·18H 2 O are the most common. The heptadecahydrate, whose formula can be written as [Al(H 2 O) 6] 2 (SO 4) 3 ·5H 2 O, occurs naturally as the ...
2 ·12H 2 O. An alum (/ ˈ æ l ə m /) is a type of chemical compound, usually a hydrated double sulfate salt of aluminium with the general formula X Al(SO 4) 2 ·12 H 2 O, such that X is a monovalent cation such as potassium or ammonium. [1] By itself, "alum" often refers to potassium alum, with the formula KAl(SO 4) 2 ·12 H 2 O.
The only stable chalcogenides under normal conditions are aluminium sulfide (Al 2 S 3), selenide (Al 2 Se 3), and telluride (Al 2 Te 3). All three are prepared by direct reaction of their elements at about 1,000 °C (1,832 °F) and quickly hydrolyse completely in water to yield aluminium hydroxide and the respective hydrogen chalcogenide .
The screw itself should be drilled a minimum of 1" into the concrete to hold effectively and a maximum of 1-3/4" or the threads will wear and will lose holding power. Ideally 1-1/4" to 1-1/2" of screw thread in the concrete. [1] So for example, if a 1/2" board is being screwed onto the concrete, a 1-3/4" to 2" concrete screw should be used ...
In 200 series stainless steels the structure is obtained by adding manganese and nitrogen, with a small amount of nickel content, making 200 series a cost-effective nickel-chromium austenitic type stainless steel. 300 series stainless steels are the larger subgroup. The most common austenitic stainless steel and most common of all stainless ...
A hex screw drive uses six-sided fastener heads, and the fastener is known as a hex head cap screw. It can be turned with an adjustable wrench, combination wrench and 6- or 12-point sockets. The hex drive is better than square drive for locations where surrounding obstacles limit wrenching access, because smaller wrench-swing arcs can still ...
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.
length and thread class fit for both barrel and screw. The more thread depth, the more difficult these parts are to manufacture, and the more expensive. Head style the most common head style for a mating fastener is a "truss" head. Other head styles are button, flat, grommet, hex head, large truss, low profile, oval, rivet and T-head. Drive systems