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Corrosion may occur where stale sewage generates hydrogen sulfide gas into an atmosphere containing oxygen gas and high relative humidity. There must be an underlying anaerobic aquatic habitat containing sulfates and an overlying aerobic aquatic habitat separated by a gas phase containing both oxygen and hydrogen sulfide at concentrations in excess of 2 ppm.
Sulfuric(IV) acid (United Kingdom spelling: sulphuric(IV) acid), also known as sulfurous (UK: sulphurous) acid and thionic acid, [citation needed] is the chemical compound with the formula H 2 SO 3. Raman spectra of solutions of sulfur dioxide in water show only signals due to the SO 2 molecule and the bisulfite ion, HSO − 3 . [ 2 ]
Various treatments are used to slow corrosion damage to metallic objects which are exposed to the weather, salt water, acids, or other hostile environments. Some unprotected metallic alloys are extremely vulnerable to corrosion, such as those used in neodymium magnets , which can spall or crumble into powder even in dry, temperature-stable ...
Anhydrous nitric acid, referred to as white fuming nitric acid, can be used to prepare water-free nitration mixtures, and this method is used in laboratory scale operations where the cost of material is not of primary importance. Fuming nitric acid is hazardous to handle and transport, because it is extremely corrosive and volatile.
Hydroxylammonium sulfate is prepared industrially via the Raschig hydroxylamine process, which involves the reduction of nitrite with bisulfite.This initially gives hydroxylamine disulfonate, which is hydrolysed to hydroxylammonium sulfate: [2] It can also be obtained by the acid-base reaction of hydroxylamine with sulfuric acid:
To avoid splattering, the concentrated acid is usually added to water and not the other way around. A saying used to remember this is "Do like you oughta, add the acid to the water". [55] [better source needed] Water has a higher heat capacity than the acid, and so a vessel of cold water will absorb heat as acid is added.
It is slightly soluble in water and acts as a weak acid (pK a = 6.9 in 0.01–0.1 mol/litre solutions at 18 °C), giving the hydrosulfide ion HS −. Hydrogen sulfide and its solutions are colorless. When exposed to air, it slowly oxidizes to form elemental sulfur, which is not soluble in water. The sulfide anion S 2− is not formed in aqueous ...
Molecular models of the different molecules active in Piranha solution: peroxysulfuric acid (H 2 SO 5) and hydrogen peroxide (H 2 O 2). Piranha solution, also known as piranha etch, is a mixture of sulfuric acid (H 2 SO 4) and hydrogen peroxide (H 2 O 2). The resulting mixture is used to clean organic residues off substrates, for example ...