Percent solutions

Impurities such as chloride ion or other reducing agents generate chlorine dioxide when the chloric acid solution is heated. Transition-metal ions do not affect the stabiUty of pure chloric acid at room temperature. Thirty-five percent solutions of HCIO have been shown to be stable for 20 days at room temperature containing up to 1000 ppm Ni ", 800 ppm Zn ", 700 ppm Fe ", or 600 ppm Cr " (2). The solubiUty of chloric acid in water is shown in Figure 1. 

For concentrated binary nonpolar liquid systems (more than 5 mole percent solute), the diffiisivity can be estimated by a molar average mixing rule developed by Caldwell and Babb, " Eq. (2-156). 

Corrective Action Application Case 1 - A spill occurred at the Houston Chemical Company (located in Texas County, Missouri) in June 1979 (U.S. EPA, 1984). An estimated 15,000 gallons of a 5 percent solution of pentachlorophenol (PCP) in diesel oil was released as shown in Figure 27. The emergency physical cleanup operations performed at the site were ... 

The commercial dry alum most often used in wastewater treatment is known as filter alum, and has the approximate chemical formula A 12(804)3 T4H2O and a molecular weight of about 600. Alum is white to cream in color and a 1 percent solution has a pH of about 3.5. The conunercially available grades of alum and their corresponding bulk densities and angles of repose are given in Table 1. 

Dense soda ash is generally used in munieipal applications because of superior handling charaeteristies. It has little dust, good flow eharaeteristics, and will not areh in the bin or flood and feeder. It is relatively hard to dissolve and ample dissolver capacity must be provided. Normal practiee calls for 0.5 lb of dense soda ash per gallon of water or a 6 percent solution retained for 20 minutes in the dissolver. 

Anhydrous caustic soda (NaOH) is available but its use is generally not considered practical in water and wastewater treatment applications. Consequently, only liquid caustic soda is discussed here. Liquid caustic soda is generally shipped at two concentrations, 50 percent and 73 percent NaOH. The densities of the solutions as shipped are 12.76 Ib/gal for the 50 percent solution and 14.18 Ib/gal for the 73 percent solution. These solutions contain 6.38 Ib/gal NaOH and 10.34 Ib/gal NaOH, respectively. The crystallization temperature is 53 F for the 50 percent solution and 165 F for the 73 percent solution. The molecular weight of NaOH is 40. The pH of a 1 percent solution of caustic soda is 12.9. 

Storage tanks for liquid caustic soda should be provided with an air vent for gravity flow. The storage capacity should be equal to 1.5 times the largest expected delivery, with an allowance for dilution water, if used, or two-weeks supply at the anticipated feed rate, whichever is greater. Tanks for storing 50 percent solution... 

Hydroquinone in a 2 percent solution is used in many skin-lightening creams and gels to remove freckles, age spots, and other hyper-pigmented areas of the skin. 

Sodium hypochlorite is usually sold in solution in water, where it makes a greenish-yellow liquid. (It is too hygroscopic—it absorbs water from the air—to be used conveniently in solid form.) Household bleaches usually contain sodium hypochlorite in a 3 percent to 6 percent solution. Some sodium hydroxide (lye) is added to keep the pH high to avoid decomposition. If the solution is made more acidic, sodium hypochlorite will dissociate, producing chlorine gas and oxygen. 

The A. niger PG preparation was suitably diluted with distilled water and was used as the enzyme source. Polygalacturonic acid was prepared as a one percent solution of in distilled water. 

Pollution Control Pervaporation is used to reduce the organic loading of a waste stream, thus effecting product recovery and a reduction in waste-treatment costs. An illustration is a waste stream containing II percent (wt) n-propanol. The residue is stripped to 0.5 percent and 96 percent of the alcohol is recovered in the permeate as a 45 percent solution. This application uses a hydrophobic, rubbery membrane. The residue is sent to a conventional waste-treatment plant. 

The alkyl methacrylate monomers were available from various sources. Isobutyl methacrylate (IBMA) (Rohm and Haas) and t-butyl methacrylate (TBMA) (Rohm Tech) may be purified first by distillation from CaH, followed by distillation from trialkyl aluminum reagents as described in detail earlier (20,21). In particular, t-butyl methacrylate (b.pt. 150°C) was successfully purified by distillation, from triethyl aluminum containing small amounts of diisobutyl aluminum hydride. The trialkyl aluminum and dialkyl aluminum hydride reagents were obtained from the Ethyl Corporation as 25 weight percent solutions in hexane. The initiator, -butyllithium, was obtained from the Lithco Division of FMC, and analyzed by the Gilman "double titration" (22). 

Proton and carbon-13 nuclear magnetic resonance (NMR) spectra were recorded on a IBM Instruments 270 MHz NMR Spectrometer on 6-8 weight percent solutions in deuterated chloroform. Ultraviolet spectra were recorded on an IBM Ultraviolet Spectropluitometer Model 9420 using chloroform solutions containing 2 x 10-5 g/ml of the copolymers. 

Add 3 ml of the detergent Brij-35 (as a 30 percent solution) and 2 ml of 2-mercaptoethanol to 950 ml of Fluoraldehyde Reagent Diluent (all reagents from Thermo Fisher). 

To obtain acceptable yields, the Mannich reaction must be done at elevated temperatures. Incubation at 37-57°C for at least 2-24 hours usually is required to complete the reaction. Addition of formaldehyde is done by adding an aliquot of a 37 percent solution to the reaction to obtain about a 10- to 100-fold molar excess over t he amount of active-hydrogen-containing... 

Analyze the NHS-palmitate for purity using TLC on silica plates. Develop using a solvent mixture of chloroforrmpetroleum diethyl ether (bp 40-60°C) of 8 2. Excess NHS and NHS-palmitate may be detected by staining with 10 percent hydroxylamine in 0.1 N NaOH, followed after 2 minutes by a 5 percent solution of FeCl3 in 1.2 N HC1 (creates red colored spots). 

Murrell, who reported in 1879 that a one percent solution of the drug administered sublingually relieved angina and prevented attacks thereafter [2],... 

In preparing smaller amounts of either STB (supertropical bleach) or HTH (calcium hypochlorite) solution, the following mixture would apply. For a 5 percent solution, mix... 

Sodium Hypochlorite Solution (household bleach) can be used against both chemical and biological agents. It is effective and fast-acting against blister and V nerve agents, but requires a contact time of ten to fifteen minutes for all biological materials. It is available in food stores as a 5 percent solution under various brand names, and as a 14 to 10 percent solution at commercial laundries. Undiluted, household bleach is harmful to skin and... 

Rinse Solution C A general purpose rinse to be used for both solutions A and B. Five percent solution of trisodium phosphate with each ten gallons of water. 

When volume percent solutions are prepared, the mL of the solute are diluted with solvent to the required volume. 

Disinfectants are applied to inanimate objects such as floors, drainage system, instruments, etc. Same substances can act as an antiseptic as well as disinfectant by varying the concentration. For example, 0.2 per cent solution of phenol is an antiseptic while its one percent solution is disinfectant. 

Two excellent examples of this membrane system have been developed, NS-lOO and PA-300 (5,15). The NS-lOO membrane was made by impregnating a polysulfone support with a 0.67 percent aqueous solution of polyethylenlmine, draining away excess reagent, then contacting the film with a 0.1 percent solution of toluenediisocyanate in hexane. An ultrathln polyurea barrier layer formed at the interface. This membrane was then heat-cured at 110°C. A later version of this membrane was developed (designated NS-101), which used isophthaloyl chloride in place of toluenedilsocyanate, producing a polyamide (16). With either type of membrane, salt rejections in simulated seawater tests at 1000 psi exceeded 99 percent. 

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