Hydrochloric acid, HCl

The raw precious metal concentrate is totally dissolved in hydrochloric acid—chlorine solution to form the soluble chloride ions of each of the metals. Silver remains as insoluble silver chloride and can be filtered off. Gold, in the form of [AuClJ, is extracted with, eg, tributyl phosphite or methyl isobutyl ketone. Base metals are also extracted in this step, and are removed from the organic phase by scmbbing with dilute hydrochloric acid (HCl). Iron powder is then used to reduce the gold species and recover them from the organic phase. 

Compound (1) decomposes to form dichloroacetyl chloride, which in the presence of water decomposes to dichloroacetic acid and hydrochloric acid (HCl) with consequent increases in the corrosive action of the solvent on metal surfaces. Compound (2) decomposes to yield phosgene, carbon monoxide, and hydrogen chloride with an increase in the corrosive action on metal surfaces. 

The most commonly used acids in preplate processes are hydrochloric acid, HCl, more common for mst and scale removal, and sulfuric acid,... 

Chlorination of thiiranes in hydroxylic solvents gives /3-chloroethylsulfonyl chlorides due to further oxidation of the intermediate sulfenyl chloride by chlorine or hypochlorous acid (Scheme 40). Polymer is usually obtained also unless the reaction is done in concentrated hydrochloric acid, which causes rapid ring cleavage to 2-chloroethylthiols which are subsequently oxidized to the sulfonyl chlorides. An 85% yield of (37) is obtained in concentrated hydrochloric acid-HCl(g) whereas only a 15% yield is obtained in CCI4-H2O. 

Perchloric acid (79% HCIO4/CH2CI2, 0°, 1 h 25°, 3 h, 87% yield) and periodic acid (aq. dioxane, 3 h, quant, yield) cleave 1,3-dioxolanes the latter drives the reaction to completion by oxidation of the ethylene glycol that forms. Yields are substantially higher from cleavage with perchloric acid (3 AHCIO4/THF, 25°, 3 h, 80% yield) than with hydrochloric acid (HCl/HOAc, 65% yield)... 

Acid pickling This can be done under the following operating conditions, either with sulphuric acid (H2SO4), or hydrochloric acid (HCl). H2SO4 releases a lot of fumes and is ineffective under cold conditions. It forms iron sulphate, which forms a hard deposit at the bottom of the tank and is difficult to remove (see table on next page). 

Hundreds of chemical species are present in urban atmospheres. The gaseous air pollutants most commonly monitored are CO, O3, NO2, SO2, and nonmethane volatile organic compounds (NMVOCs), Measurement of specific hydrocarbon compounds is becoming routine in the United States for two reasons (1) their potential role as air toxics and (2) the need for detailed hydrocarbon data for control of urban ozone concentrations. Hydrochloric acid (HCl), ammonia (NH3), and hydrogen fluoride (HF) are occasionally measured. Calibration standards and procedures are available for all of these analytic techniques, ensuring the quality of the analytical results... 

Hydrochloric acid (HCl) is a strong acid in water at dissociates completely into (more accurately, H3O and Cr. 

Hydrochloric acid (HCL) Water-treatment plant (cation) 165kg/day at 30% solution... 

Aqueous hydrochloric acid, HCl, is usually sold as a 12.0-M solution, commonly referred to as concentrated HCl. A chemist needs to prepare 2.00 L of 1.50 M HCl for a number of different applications. What volume of concentrated HCl solution should the chemist use in the dilution ... 

An exampie of diffttsion is shown in Figure 5-15. in which aqueous solutions of hydrochloric acid (HCl) and... 

Horizontal completions in unconsolidated formations are being enhanced by a hydrochloric acid (HCl) breaker system for well clean up. Typically, the use of HCl in open-hole environments is avoided because of wellbore stability concerns. However, HCl successfully removes salt fluid loss control materials in wells without noticeable hole collapse [33]. 

The diagram shows the activity series of some metals (left) and nonmetals (right). A student set up four beakers, each containing 100 mL of dilute hydrochloric acid (HCl[aq]). She added 5 g of a metal to each beaker in this order aluminum (Al), copper (Cu), sodium (Na), and zinc (Zn). Which metal will NOT react with the acid ... 

Ethyl acetate, Pesticide Grade, J.T. Baker Hexane, Resi-Analyzed, J.T. Baker Hydrochloric acid (HCl, 36.5-38.0%), J.T. Baker Hydrion pH buffer, VWR (cat. No. 34175-220)... 

Anhydrous sodium sulfate, special grade Sodium hydroxide (Na OH), special grade Hydrochloric acid (HCl), special grade Aluminum oxide 90, neutral, activity grade II-III (Merck)... 

Macerated plant material is homogenized with a mixture of methanol and 1.2N hydrochloric acid (HCl) in water (4 1, v/v) and then with methanol. An internal standard solution is added to the filtrate and the filtrate is adjusted to a constant volume. A portion of the filtrate is rotary evaporated to dryness and hexane is added to the extract before a Florisil cleanup procedure is performed. The extract is dissolved in toluene for analysis by GC/MS in the negative chemical ionization (NCI) mode. 

American Chemistry Council. Hydrochloric acid-HCl—an acid with many uses. Available online. URL http //www. americanchemistry.com/s chlorine/science sec.asp CID= 1255 DID=4735 CTYPEID= 113. Accessed on March 17, 2008. 

Hydrochloric acid (HCl), a strong acid that dissociates into an H+ and a CP ion, is produced by the parietal cells. These ions are actively transported into the lumen of the stomach by the proton pump. Functions of HCl include ... 

Solution D A diluted solution of hydrochloric acid (HCL). Mix one pint of concentrated HCL into ten gallons of water (acid to water only). Stir with wood or plastic stirrer. 

An acid is a substance that dissociates in water to form H q). Two examples of Arrhenius acids are hydrochloric acid, HCl, and sulfuric acid, H2SO4. 

Br, and I (but not F) for example, hydrochloric acid, HCl, and hydrobromic acid, HBr (HCl and HBr are hydrohalic acids acids that have hydrogen bonded to atoms of the halogen elements.)... 

For example, the conjugate base of hydrochloric acid, HCl, is Cl . The chloride ion is a very weak base, so it does not react significantly with water. Therefore, the chloride ion, and the conjugate bases of other strong acids, do not affect the pH of an aqueous solution. 

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