Modified methyl orange

A 0.527-g sample of a mixture containing NaCOj. NaHCOj, and inert impurities is titrated with 0.109 M HCl, requiring 15.7 mL to reach the phenolph-thalein end point and a total of 43.8 mL to reach the modified methyl orange end point. What is the percent each of Na2C03 and NaHCOs in the mixture ... 

NaHC03 is titrated with HCl. The phenolphthalein end point occurs at 15.0 mL and the modified methyl orange end point occurs at 50.0 mL (35.0 mL beyond the first end point). The HCl was standardized by titrating 0.477 g Na2C03, requiring 30.0 mL to reach the modified methyl orange end point. What mixture is present and how many millimoles of each constiment are present ... 

Provided. 0.2% phenolphthalein in 90% ethanol, either modified methyl orange (mixture of methyl orange and xylene cylanole FF available from East-m Kodak Co.) or 0.1% bromcresol green in 0.001 M NaOH, and either primary standard Na2C03 or standardized 0.1 M NaOH. 

Total Alkalinity is determined by titration with standard hydrochloric acid solution using methyl orange indicator solution or modified methyl orange indicator solution Sodium Carbonate or Potassium Carbonate (Gas-volumetric method, the lower limit of determination is 0.001 g as carbon dioxide) Carbon dioxide is evolved by acid decomposition of carbonate in the sample. The volume of CO2 is measured and calculated as sodium or potassium carbonate. 

Deri here (Ref 3) modified these methods by adding the water, used for washing the gases evolved during the stabilization test, directly to the container in which the proplnt had been heated and determining the pH colorimetrically (instead of electrometrically) by a series of sensitive indicators (thymol blue for pH 2 to 3 3 btomophenol blue 2.8 to 4.6, bromocresol green 3.6 to 4.8 methyl orange 3.S to 5 2 bromocresol purple 5-2 to 6,8 and bromothymol blue 6.0 to 7.6)... 

Methyl orange, modified. Dissolve 2 g of methyl orange and 2.8 g of xylene cyanole FF in 1 L of 50% alcohol. 

D. Wang, J. Zhang, Q. Luo, X. Li, Y. Duan, J. An, Characterization and photocatalytic activity of poly(3-hexylthiophene)-modified Ti02 for degradation of methyl orange under visible light . Journal of Hazardous Materials, 169, 546-550, (2009). 

There are two suggested eolorimetric methods for BCHI analysis in neat and residual samples. One method is based on methyl orange colorimetric determination and the other method is based on iodine complexation (iodometric). The methyl orange colorimetric method is subjeet to intense interference by Cl and it could not be employed for KHI determination in the presence of Cl blends. The iodine complexation method is chosen as a practieal wet chemical method for BCHI analysis. It is modified to minimize the interferences due to brine concentration. Cl components, condensate, and sulfide. However, the seleetivity of the iodine complexation method is still not at the desired level. As an improvement to selectivity and accuracy for BCHI determination, a size exclusion chromatography (SEC) method [8] was evaluated. 

An elegant experiment by Crooks showed that the hydrophobic modification of PAMAM dendrimers by noncovalent interactions could also result in macromolecules that behave like inverted micelles (118). The spontaneous assembly between the fatty acids and amino periphery of the PAMAM dendrimer was driven by ionic interactions (Fig. 32). These dendrimers were shown to be capable of extracting hydrophilic dyes such as methyl orange fi om water into toluene. Similarly, these dendrimers were also shown to be excellent molecular containers for catalytically active metal nanoparticles. The inverted micellar nature of various dendrimers have been used by Crooks and others for the preparation of a variety of nanoparticles (119-122). A related macromolecule, but an architecture with less of a control, is a hyperbranched polymer. Hydrophobically modified hyperbranched polymers have also been shown to be capable of acting as inverted micelles (123,124). 

IL-based surfactants as modifiers ofNa-Bt surfaces, followed by extraction/ removal of methyl orange Vortex (3 min)... 

The use of modified polyethylenimines was initiated by Klotz et al (21) in binding studies of acylated polyethylenimine with bovine serum albumin and methyl orange. This same group in 1971 applied a similarly modified polyethylenimine containing imidazole groups to the solvolysis of phenyl esters. Because of polyethylenimine s different chemical nature and related solubility properties, polyethylenimine was expected to provide a microenvironment dissimilar to that associated with a vinyl polymer catalyst. The second-order rate constant for the hydrolysis of p-nitrophenylacetate with the modified polyethylenimine, D(10%)-PEI-Im(15%) [10% dodecyl groups,... 

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