Hydrochloric acid standard

Show by calculation which of the following metals will react with hydrochloric acid (standard concentrations). 

C04-0034. While cleaning a laboratory, a technician discovers a large bottle containing a colorless solution. The bottle is labeled Ba (OH)2, but the molarity of the solution is not given. Concerned because of the toxicity of Ba ions, the technician titrates with a solution of hydrochloric acid standardized at 0.1374 M. A 25.00-mL sample of the barium hydroxide solution requires 36.72 mL of the HCl solution to reach the stoichiometric point. What is the concentration of Ba in the solution ... 

The method is suitable for the determination of Ca, Fe, V, Ba, Ni, Na and Mg in crude and residual fuel oils. It may also be applicable to other elements. The oil is ashed to obtain the inorganic residue and the ash taken up in hydrochloric acid. Standards are prepared in hydrochloric acid media. Limits of detection will lie between 0.1 and lpgg-1 for most elements. 

Scott [48] has determined europium in yttrium phosphors. Yttrium vanadate (0.1 g) was fused with potassium carbonate (2g) in a platinum crucible. Yttrium oxide and yttrium oxysulphide can be dissolved directly in the same solvent as the above melt, 50% hydrochloric acid. Standard flame conditions for yttrium were used. 

For analysis of acids, esters, alcohols, ketones, aldehydes and fiirfiual the test solution was prepared by dilution of a weighed sam de of clear ftaction of the condensate 10 g to 100 ml with distillate water. The content of acids and esters was determined by potentiometric titration, using potassium hydroxide and hydrochloric acid standard volumetric solutions. c(KOH) = 0.1 mol/l c(HCl) = 0.1 molfi. An automatic potentiometric titration assembly RTS - 822 Radiometer (Denmark) was used. 

Thus under standard conditions chloride ions are not oxidised to chlorine by dichromate(Vr) ions. However, it is necessary to emphasise that changes in the concentration of the dichromate(VI) and chloride ions alters their redox potentials as indicated by the Nernst equation. Hence, when concentrated hydrochloric acid is added to solid potassium dichromate and the mixture warmed, chlorine is liberated. 

The anhydrous chloride is prepared by standard methods. It is readily soluble in water to give a blue-green solution from which the blue hydrated salt CuClj. 2H2O can be crystallised here, two water molecules replace two of the planar chlorine ligands in the structure given above. Addition of dilute hydrochloric acid to copper(II) hydroxide or carbonate also gives a blue-green solution of the chloride CuClj but addition of concentrated hydrochloric acid (or any source of chloride ion) produces a yellow solution due to formation of chloro-copper(ll) complexes (see below). 

Nitro groups are readily reduced to primary amines by a variety of methods Cat alytic hydrogenation over platinum palladium or nickel is often used as is reduction by iron or tin m hydrochloric acid The ease with which nitro groups are reduced is especially useful m the preparation of arylamines where the sequence ArH ArN02 ArNH2 IS the standard route to these compounds... 

THPC—Amide Process. The THPC—amide process is the first practical process based on THPC. It consists of a combination of THPC, TMM, and urea. In this process, there is the potential of polymer formation by THPC, melamine, and urea. There may also be some limited cross-linking between cellulose and the TMM system. The formulation also includes triethanolamine [102-71-6J, an acid scavenger, which slows polymerization at room temperature. Urea and triethanolamine react with the hydrochloric acid produced in the polymerization reaction, thus preventing acid damage to the fabric. This finish with suitable add-on passes the standard vertical flame test after repeated laundering (80). 

Commercial Hquid sodium alumiaates are normally analyzed for total alumiaa and for sodium oxide by titration with ethylene diaminetetraacetic acid [60-00-4] (EDTA) or hydrochloric acid. Further analysis iacludes the determiaation of soluble alumiaa, soluble siHca, total iasoluble material, sodium oxide content, and carbon dioxide. Aluminum and sodium can also be determiaed by emission spectroscopy. The total iasoluble material is determiaed by weighing the ignited residue after extraction of the soluble material with sodium hydroxide. The sodium oxide content is determiaed ia a flame photometer by comparison to proper standards. Carbon dioxide is usually determiaed by the amount evolved, as ia the Underwood method. 

A double end point, acid—base titration can be used to determine both sodium hydrosulfide and sodium sulfide content. Standardized hydrochloric acid is the titrant thymolphthalein and bromophenol blue are the indicators. Other bases having ionization constants in the ranges of the indicators used interfere with the analysis. Sodium thiosulfate and sodium thiocarbonate interfere quantitatively with the accuracy of the results. Detailed procedures to analyze sodium sulfide, sodium hydro sulfide, and sodium tetrasulfide are available (1). 

Analytical and Laboratory Operations. Sulfamic acid has been recommended as a reference standard in acidimetry (55). It can be purified by recrystaUization to give a stable product that is 99.95 wt % pure. The reaction with nitrite as used in the sulfamic acid analytical method has also been adapted for determination of nitrites with the acid as the reagent. This reaction is used commercially in other systems for removal of nitrous acid impurities, eg, in sulfuric and hydrochloric acid purification operations. 

Tin ores and concentrates can be brought into solution by fusing at red heat in a nickel cmcible with sodium carbonate and sodium peroxide, leaching in water, acidifying with hydrochloric acid, and digesting with nickel sheet. The solution is cooled in carbon dioxide, and titrated with a standard potassium iodate—iodide solution using starch as an indicator. 

The standard manufacturing method for tetraalkyl titanates, such as TYZOR TPT, or tetra- -butyi titanate, TYZOR TBT [5593-70 ] involves the addition of TiCl to an alcohol. In a series of reversible displacement reactions, the alkoxy substitution products and hydrochloric acid form as follows ... 

The assay method involves the reaction of benzaldehyde with hydroxylamine hydrochloride in an alcohoHc solution. Benzaldehyde oxime, water, and hydrochloric acid are the products of the reaction. The hydrochloric acid formed is then titrated with standard caustic solution to determine the benzaldehyde assay. 

The sodium carbonate content may be deterrnined on the same sample after a slight excess of silver nitrate has been added. An excess of barium chloride solution is added and, after the barium carbonate has setded, it is filtered, washed, and decomposed by boiling with an excess of standard hydrochloric acid. The excess of acid is then titrated with standard sodium hydroxide solution, using methyl red as indicator, and the sodium carbonate content is calculated. 

The preparation of cyclohexylmagnesium bromide is described on p. 22. The solution may be standardized by titrating against 0.5 N hydrochloric acid, and exactly one mole equivalent is used in the preparation. Five cubic centimeters of cyclohexylmagnesium bromide solution is slowly added to 20 cc. of water, an excess of the standard acid is added, and the excess acid titrated with sodium hydroxide. If 85 g. (3.5 moles) of magnesium, one liter of dry ether, and 571 g. of cyclohexyl bromide (3.5 moles) are used, a solution results which is about 2 molar. 

Caution tevt-Butyllithium ie pyvophovia in air exaeee quantities of the reagent in the syringe should be discarded oery carefully- The checkers used the reagent available from Aldrich Chemical Company Ltd., England and standardized it by double titration with ethylene dibromide and hydrochloric acid. ... 

One 1-ml aliquot is added to 1.0 ml of freshly-distilled 1,2-dibromo-ethane (bp 132°C) in an oven-dried flask which contains a static atmosphere of nitrogen or argon. After the resulting solution has been allowed to stand at 25°C for 5 min, it Is diluted with 10 rat of water and titrated for base content (residual base) to a phenolphthalein endpoint with standard 0.100 M hydrochloric acid. The second 1-mL aliquot is added cautiously to 10 ml of water and then titrated for base content (total base) to a phenol phthalein endpoint with standard aqueous 0.100 M hydrochloric acid. The methyllithium concentration is the difference between the total base and residual base concentrations.2 Alternatively, the methynithiura concentration may be determined by titration with a standard solution of sec-butyl alcohol employing 2,2 -bipyridyl as an indicator. 

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... 

Sand that is used in filtration must be free of clay, dust, and other impurities. The ratio of lime, lime-stone, and magnesium oxide will have to be lower than 5 weight percent. The standard guide value of the quality of fresh sand is to be below 2% soluble matter at 20 °C within 24 hours in hydrochloric acid of a 20 weight percent concentration. 

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