Temperature titration

Esterified Carboxyl Groups Quantitatively transfer the solution obtained in the determination of Free Carboxyl Groups (below) into a 1-L Erlenmeyer flask, add a few drops of phenolphthalein TS and 50.0 mL of 0.1 N sodium hydroxide. Stopper the flask, swirl the solution, and then allow it to stand for 30 min at room temperature. Titrate the excess sodium hydroxide to a faint pink endpoint with 0.1 A hydrochloric acid. Transfer the solution to a 600-mL beaker, and complete the titration to a pH of 7.0, determining the endpoint potentio-metrically. Calculate the percentage of esterified carboxyl groups by the formula... 

Assay Transfer about 250 mg of sample, previously dried at 150° for 3 h and accurately weighed, to a 250-mL beaker. Add 150 mL of glacial acetic acid, heat to near boiling, stir (preferably with a magnetic stirrer) until the sample is dissolved, and cool to room temperature. Titrate with 0.1 A perchloric acid in glacial acetic acid, determining the endpoint potentiometrically. 

Procedure Transfer an accurately weighed quantity of sample, as specified below, into a 250-mL glass-stoppered flask. Add 75.0 mL of Hydroxylamine Solution to this flask and to a similar flask for a residual blank titration (see General Provisions). Attach the flask to a suitable condenser, reflux the mixture for the time specified, and then cool to room temperature. Titrate both flasks with 0.5 N hydrochloric acid to the same green-yellow endpoint using bromophenol blue TS as the indicator or, preferably, using a pH meter, to a pH of 3.4. (If the indicator is used, the endpoint color must be the same as that produced when the blank is titrated to a pH of 3.4.) Calculate the percent ketone by the equation... 

Symbol Synthesis Temperature Titration Letter(s) designation for an element. When many substances come together to form one compound. Average kinetic energy possessed by a sample. The process by which acids and bases can be measured out in exact quantities so that they neutralize each other exactly and without any excess. 

Also, for platinum, a room-temperature titration of oxygen adsorbed on the metal with gaseous hydrogen (24-26) has become a very valuable method, particularly when interference by the support is to be feared, e.g., for catalysts with small amounts of metal (27). 

Ghasemi, J.B., Mandoumi, N.A. (2008). New algorithm for the characterization of thermodynamics of monomer-dimer process of dye stuffs by photometric temperature titration. Acta Chim. Slav. Vol. 55. p>p. 377-384. 

In the first approximation, no precipitation of the fractions within this MW range could be expected in a polymolecular polymer sample. Comparison of the segments A R and. 91) indicates that the increase in the precipitated content from 0.75 to 0.85 results in partial dissolution of the previously precipitated polymer in the system PoMS+cyclohexane-l-oc-tanol due to the decrease in the total polymer concentration. The effect of repeat dissolution is specific for precipitation TT and is not observed in temperature titration. 

Dissolve about 0 4 g of sample in 20 ml of N sodium hydroxide and add 40 to 60 ml of hydrogen peroxide solution (20 vol). Heat on a water-bath until all effervescence has ceased, then cool to room temperature. Titrate the excess of sodium hydroxide with N hydrochloric acid using phenolphthalein as indicator. Repeat the determination omitting the vanillin. 1 ml of N NaOH = 0-2954 g of CgHsOg. 

Adjust the flow of the gases, the pyrolysis furnace temperature, titration cell, and the coulometer to the desired operating conditions. Typical operational conditions are given in Table 1. 

Cloud Temperature Titration (CT) In a variation of the cloud point titration method, cloud temperatures may be determined by cooling or heating of dilute polymer... 

Transfer 25 ml. of this dilute solution by means of a pipette to a conical flask, and add similarly 50 ml. of Ml 10 iodine solution. Now-add 10% sodium hydroxide solution until the liquid becomes pale yeilow in colour, and allow the solution to stand, with occasional shaking, at room temperature for at least 10 minutes. Then acidify with dilute hydrochloric acid (free from chlorine) in order to liberate the remaining iodine. Titrate the latter w ith Mho sodium thiosulphate solution, using starch as an indicator in the usual way. 

The number of ethylenic linkages In a given compound can be established with accuracy by quantitative titration with perbenzoic acid. A solution of the substance ajid excess of perbenzoic acid in chloroform is allowed to stand for several hours at a low temperature and the amount of unreacted perbenzoic acid in solution is determined a blank experiment is run simultaneously. 

Concentration is not the only property that may be used to construct a titration curve. Other parameters, such as temperature or the absorbance of light, may be used if they show a significant change in value at the equivalence point. Many titration reactions, for example, are exothermic. As the titrant and analyte react, the temperature of the system steadily increases. Once the titration is complete, further additions of titrant do not produce as exothermic a response, and the change in temperature levels off. A typical titration curve of temperature versus volume of titrant is shown in Figure 9.3. The titration curve contains two linear segments, the intersection of which marks the equivalence point. 

Finding the End Point by Monitoring Temperature The reaction between an acid and a base is exothermic. Heat generated by the reaction increases the temperature of the titration mixture. The progress of the titration, therefore, can be followed by monitoring the change in temperature. 

A quantitative analysis for NH3 in several household cleaning products is carried out by titrating with a standard solution of HGl. The titration s progress is followed thermometrically by monitoring the temperature of the titration mixture as a function of the volume of added titrant. Household cleaning products may contain other basic components, such as sodium citrate or sodium carbonate, that will also be titrated by HGl. By comparing titration curves for prepared samples of NH3 to titration curves for the samples, it is possible to determine that portion of the thermometric titration curve due to the neutralization of NH3. 

Binary mixtures of Ga + and Mg +, and ternary mixtures of Ga +, Mg +, and Ba + are determined by titrating with EDTA. The progress of the titration is followed thermometrically. Gomplexation of Ga + and Ba + with EDTA is exothermic, whereas complexation of Mg + with EDTA is endothermic. As EDTA is added, the temperature initially rises due to the complexation of Ga +. The temperature then falls as Mg + is titrated, rising again as Ba + is titrated. 

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