Search results
Results from the WOW.Com Content Network
A 19th-century assay laboratory in Tombstone Courthouse State Historic Park, Arizona. A model of a late 19th-century Canadian seal used to certify the quality of assayed gold. A metallurgical assay is a compositional analysis of an ore, metal, or alloy, usually performed in order to test for purity or quality.
is an alkaline solution of potassium permanganate; used in organic chemistry as a qualitative test for the presence of unsaturation, such as double bonds; N-Bromosuccinimide: used in radical substitution and electrophilic addition reactions in organic chemistry. Also acts as a mild oxidizer to oxidize benzylic or allylic alcohols.
This process can be used to grow thick (tens or hundreds of micrometers), largely crystalline, oxide coatings on metals such as aluminium, magnesium [2] and titanium. Because they can present high hardness [ 3 ] and a continuous barrier, these coatings can offer protection against wear , corrosion or heat as well as electrical insulation .
Electrostatic plates can be used in addition to the magnet to increase the speed, and with multiple collectors can allow a scan of every element from Lithium 6 to Uranium Oxide 256 in less than a quarter of a second. For low detection limits, interfering species and high precision, the counting time can increase substantially.
The initial discovery came in 1997 when Cambridge University researchers immersed small samples of certain oxides in baths of molten salt and reduced the oxide with electric current. The cathode uses powdered metal oxide. The anode is made of carbon. The molten salt at 1,000 °C (1,830 °F) is the electrolyte.
Aluminium oxide is also used in preparation of coating suspensions in compact fluorescent lamps. In chemistry laboratories, aluminium oxide is a medium for chromatography, available in basic (pH 9.5), acidic (pH 4.5 when in water) and neutral formulations. Additionally, small pieces of aluminium oxide are often used as boiling chips.
Mixed metal oxide (MMO) electrodes, also called Dimensionally Stable Anodes (DSA), are devices with high conductivity and corrosion resistance for use as anodes in electrolysis. They are made by coating a substrate, such as pure titanium plate or expanded mesh, with several kinds of metal oxides.
Sodium methoxide is prepared by treating methanol with sodium: 2 Na + 2 CH 3 OH → 2 CH 3 ONa + H 2. The reaction is so exothermic that ignition is possible. The resulting solution, which is colorless, is often used as a source of sodium methoxide, but the pure material can be isolated by evaporation followed by heating to remove residual methanol.