Caustic acids

The EPA defines corrosivity in terms of pH (i.e., wastes with pH <2 or >2.5) or in terms of ability to corrode steel (SAE 20) at a rate of >6.35 mm (0.250 in.) per year at a temperature of 55 C (13°F). This discussion will address corrosivity as it applies to acids and caustics. Acids are compounds that yield H ions (actually HjO ions) when dissolved in water. Common industrial acids include acetic, nitric, hydrochloric, and sulfuric acids. The terms concentrated and dilute refer to the concentrations in solution. Mixing a concentrated acid with enough water will produce a dilute acid. For example, a bottle of concentrated HCl direct from the manufacturer is approximately 12 N in HCl, while a solution of HCl used in a titration may be only 0.5 N. The latter is a dilute acid solution. 

Chemical Reactivity - Reactivity with Wo/er.- Reacts with moisture in air forming a dense white fume. Reaction with liquid water gives off heat and forms hydrochloric acid Reactivity with Common Materials The acid formed by reaction with moisture attacks metals, forming flammable hydrogen gas Stability During Transport Stable Neutralizing Agents for Acids and Caustics Acid formed by the reaction with water can be neutralized by limestone, lime, or soda ash Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Paint stripping is the process of removing an organic coating from a workpiece. The stripping of such coatings is usually performed with caustic, acid, solvent, or molten salt. 

Acidity or causticity Acid gas release (e.g., anhydrous HC1) Corrosive liquid or solid spill Uncontrolled acid/base reaction... 

Specific segments of process piping handling flammable liquids or gases in mixtures known to promote pipe failures through erosion, corrosion, or embrittlement. These include hydrocarbons, streams that may contain entrained catalyst, caustics, acids, hydrogen, or similar materials where development of an appropriate scenario envelope is feasible. 

Examination of the mouth provides evidence of exposure to some toxicants. Caustic acids and bases cause a moist condition of the mouth. Other toxicants that cause the mouth to be moister than normal include mercury, arsenic, thallium, carbamates, and organophosphates. A dry mouth is symptomatic of poisoning by tricyclic antidepressants, amphetamines, antihistamines, and glutethimide. 

Of course, the engineer should specify items of equipment that have been designed for the proper Class, Group and Division (see Table I) as specified in the National Electrical Code (NEC). However, careful consideration must be given to the environment in which this equipment will operate. Caustics, acids and other corrosive agents can ruin electrical contact surfaces, and destroy exposed components in a short time. 

SPILL CLEAN-UP Approach release from upwind flush spill with flooding quantities of water neutralize with caustic acid solution and isolate for proper disposal remove all sources of ignition,... 

Opposed to the acids is another group of substances called bases, (Strong bases are termed alkalis.) These are also chemically active, taste bitter, change dye colors in a fashion opposite to that induced by acids, and so on. In particular, solutions of acids will neutralize solutions of bases. In other words, if acids and bases are mixed in proper proportions, then the mixture will show the property of neither acids nor bases. The mixture will be, instead, a solution of a salt, which, in general, is a much milder chemical than either an acid or a base. Thus, a solution of the strong and caustic acid, hydrochloric acid, if mixed with the proper amount of the strong and caustic alkali, sodium hydroxide, will be-... 

Synonyms Carboxylic acids, naphthenic Naphthenic acids Definition Any of a group of sat. higher fatty acids derived from gas-oil fraction of petroleum by extraction with caustic acid sol n. and subsequent acidification... 

A process for the titanate catalyzed preparation of plasticizers from polycarboxyhc acids and alcohols, which minimizes waste water and is energy efficient, has been patented. The reaction product is treated with aqueous caustic and it is then filtered using an absorbent medium which removes titanium, caustic, acid salts and water. The need for water washing is obviated, and the final plasticizer product has excellent properties. This process can be used for production of phthalates, adipates, and trimellitates."... 

Before startup of the electrolyzers, the process systems relating to the supply of electrolyzer feed streams (feed brine, caustic, acid, demineralized water) and to the product streams (depleted brine, product caustic, chlorine, hydrogen) must be commissioned and brought up to operational status ... 

The sensors are able to detect relevant quantities of agent at levels that are below those that are immediately dangerous, for the following hazards nerve, blood, and blister agents caustic acids or bases reactive aldehydes and potent oxidizers. The covalently attached enzymes make the sensors extremely sensitive and highly specific toward their target chemicals, and the immobilization within the polyurethane matrix provides the necessary robustness for a sensor application outside the laboratory environment. 

The members of this series are disulfonated alkylaryls, free acid or sodium salt. They demonstrate outstanding compatibility with caustic, acids, hypochlorite and various electrolytes. All are water soluble. They are used in alkaline and acid cleaners, liquid autodlsh products and various hard surface cleaners. They are also used for acid dye leveling and for emulsion polymerization. 

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