Metals reactivity with acids

Chemical Reactivity - Reactivity with Water Reacts violently to form hydrogen chloride, which is corrosive to metals Reactivity with Common Materials Reacts with surface moisture to evolve hydrogen chloride, which is corrosive to metals Stability During Transport Stable Neutralizing Agents for Acids and Caustics Flush with water, rinse with sodium bicarbonate or lime solution Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

The hrst production step involves recovery of the metal from spodumene. The naturahy occurring ore, alpha-spodumene is heated in a brick-lined rotary kiln at a temperature between 1,075 to 1,100°C. This converts the alpha form to a more reactive form, beta-spodumene. The beta form is heated in a rotary kiln at 250°C with an excess of 93% sulfuric acid. The metal reacts with acid forming hthium sulfate. The kiln discharge is leached with water to separate water-soluble hthium sulfate from several impurity metals. Aqueous solution containing excess sulfuric acid is then neutrahzed by treatment with an excess of ground calcium carbonate (limestone). The solution is fdtered to... 

Usually, acidic condition decreases the extraction rate of metal ions with acidic ligand, because of the suppression of the dissociation of extractant. However, in the extraction of Pd(II) with 5-Br-PADAP, the lowering of pH accelerated the extraction rate [73], The protonation of 5-Br-PADAP increased its adsorptivity but did not decrease the reactivity with Pd(II), for the nitrogen atom of imine form was protonated. The rate constant is larger for the reaction with the protonated 5-Br-PADAP than with the neutral one, because Pd(II) is coordinated by chloride ion to be charged negatively as PdClf and PdCl4. ... 

Relative Reactivities of Metals In Chapter 4, we discussed the activity series of the metals (see Figure 4.14), which ranks metals by their ability to displace one another from aqueous solution. Now you ll see why this displacement occurs, as well as why many, but not all, metals react with acid to form H2, and why a few metals form H2 even in water. 

CHEMICAL PROPERTIES corrosive to copper and zinc alloys, aluminum and galvanized surfaces may react with acids, strong oxidizers, chlorine, hypchlorite, halogenated compounds, reactive organic compounds, and some metals reactive with mercury and nitro-sating compounds FP (0°C, 32°F) LFL/UFL (4.9%, 20.7%) AT (430°C, 806°F) HC (253.5 kcal/gmol liquid at 25°C) HF (-47.3 kJ/mol liquid at 25°C). 

Toxicology LD50 (oral) 69 mg/kg, (dermal) 4-8 g/kg when moist, may cause severe irritation and skin bums sodium borate (decomp, prod.) considered si. toxic orally and nontoxic dermally Precautkm Flamm. hygroscopic very reactive with acids and under acidic conditions, with oxidizers, with transition metal ions, with lower alcohols hardens on exposure to moist air... 

Putting metals in order of reactivity with acids... 

Meta.1 Conta.mina.nts and Ash. Alkali metals form basic oxides that are very reactive toward acidic species such as the acid gases, siHcates, and alurninates. These form stable salts with acid gases if the off-gas contains such gases. Sodium, the most common of these metals, prefers to form chlorides ahead of sulfates. Sodium carbonate only forms in the absence of haHdes and sulfur oxides, SO. There usually is too Htde NO present to form nitrates (see Sodium compounds). 

Zinc and Zinc Alloys. Zinc metal is highly reactive in acid solutions such as sulfuric, hydrochloric, and nitric dissolving rapidly at acid concentrations normally used to pickle steel and aluminum. Dilute (1—4%) solutions of these acids can be used with caution to remove zinc oxides. 

Amine Cross-Linking. Two commercially important, high performance elastomers which are not normally sulfur-cured are the fluoroelastomers (FKM) and the polyacrylates (ACM). Polyacrylates typically contain a small percent of a reactive monomer designed to react with amine curatives such as hexamethylene-diamine carbamate (Diak 1). Because the type and level of reactive monomer varies with ACM type, it is important to match the curative type to the particular ACM ia questioa. Sulfur and sulfur-beating materials can be used as cure retarders they also serve as age resistors (22). Fluoroelastomer cure systems typically utilize amines as the primary cross-linking agent and metal oxides as acid acceptors. 

Many anthraquinone reactive and acid dyes are derived from bromamine acid. The bromine atom is replaced with appropriate amines in the presence of copper catalyst in water or water—alcohol mixtures in the presence of acid binding agents such as alkaU metal carbonate, bicarbonate, hydroxide, or acetate (Ullmaim condensation reaction). 

Chemical Reactivity - Reactivity with Water Dissolves and forms dilute solution of hydrofluoric acid Reactivity with Common Materials May corrode glass, cement and most metals Stability During... 

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