Methods conductometric

Hydrolysis of amide groups to carboxylate is a major cause of instability in acrylamide-based polymers, especially at alkaline pH and high temperatures. The performance of oil-recovery polymers may be adversely affected by excessive hydrolysis, which can promote precipitation from sea water solution. This work has studied the effects of the sodium salts of acrylic acid and AMPS, 2-acrylamido-2-methylpropanesulfonic acid, as comonomers, on the rate of hydrolysis of polyacrylamides in alkaline solution at high temperatures. Copolymers were prepared containing from 0-53 mole % of the anionic comonomers, and hydrolyzed in aqueous solution at pH 8.5 at 90°C, 108°C and 120°C. The extent of hydrolysis was measured by a conductometric method, analyzing for the total carboxylate content. 

Papovic et al. [14] used a conductometric method for the determination of primaquine phosphate. This method is recommended with perchloric acid, silicotungstic acid, and sodium hydroxide as titrants. Conductometric curves obtained with... 

The TBP structures of 9 I2 and 11 2I2 are noteworthy, since iodine adducts of selenides are predicted to be MC based on the general rule (x(Se) (=2.48) > xCO (=2.21)). This must be the reflection of the high ability of the imidazoline ring to donate electrons to Se by the formation of the stable cyclic 6ji system. It will decrease xeff of Se in 9 and 11 to give TBP with iodine. Since the electronic conditions in 10 must not be so different from those in 9 and 11, they should not be responsible for the different structures of the adducts. This working hypothesis is supported by DFT calculations.38 Therefore, the crystal packing effect must play a crucial role in determining the structures of the iodine adducts of 9-11. The reactions are followed by spectroscopic and conductometric methods.37... 

Electrometric methods have also been used for the final measurement of carbon dioxide Szekielda and Krey [146] devised a conductometric method. By far the most popular methods, however, have used commercial CHN analysers for the final measurement [147-150]. The actual measurement of carbon... 

The kinetics of various ligand exchange reactions have been studied by the conductometric methods. 

Besides, the aforesaid visual methods of assay i.e., observing the change in colour of indicators used, alternative instrumental methods such as potentiometric, amperometric, polarographic, conductometric methods are also employed in determining the end-point. 

U) Non-Faradaic electrochemical methods. Conductometric methods have been extensively used by scientists and conservators for monitoring the content of salts removed during water immersion treatments of ancient tiles and archaeological ceramic remains. In a different manner to IC, this technique provides the total ionic... 

Conductometric method of analysis of nitric-sulfuric acid mixtures 3 C498... 

Conductometric Method of Analysis of Nitric-Sulfuric Acid Mixtures. See Y. Lacroix M. 

Conductometric methods in conductometric methods, the conductivity of an electrolyte is assessed by measuring the impedance of this system using two identical electrodes, planarly positioned. However, much more can be done if the impedance is measured as a function of applied frequency, a method that is called electrochemical impedance spectroscopy more details about this method are given in section2.3. 

However, p-jump techniques are not without fault (Takahashi and Alberty, 1969). Most chemical reactions are less sensitive to pressure than to temperature alterations. Thus, a highly sensitive detection method such as conductivity must be employed to measure relaxation times if p-jump is used. Conductometric methods are sensitive on an absolute basis, but it is also fundamental that the solutions under study have adequate buffering and proper ionic strengths. In relaxation techniques, small molar volume changes result, and consequently, even if a low level of an inert electrolyte is present, conductivity changes may be undetectable if pressure perturbations of 5-10 MPa are utilized (Takahashi and Alberty, 1969). 

The conductometric titration method has several advantages over the potentiometric titration method. It is applicable in a straight forward manner, without back titration or other modifications, to the determination of TBN for a wide range of petroleum products including fresh and heavily used oils. The conductometric method is quick and easy to perform, with two intersecting lines at the equivalent point, also contamination of electrodes is eliminated. The... 

The TBN values obtained for the fresh, unused, lubricating oil additive package components show results from conductometric and IP 177 (potentiometric) methods being 90% to 98 % and 85% to 90%, respectively, of the corresponding IP 276 (potentiometric) values. The TBN values for some selective products such as zinc dialkyl-dithiophosphate (ZDDP) was observed as an inflection point using the IP 276 (potentiometric) back titration method and also the conductometric method. 

Table 6.4. Comparative experimental TBN [mg KOH g1] values obtained by the potentiometric and conductometric method for petroleum products (Fox et al., 1991)...

The conductometric method is superior to the current standard potentiometric methods, with the advantages of ... 

The conductometric method is generally more convenient and reproducible than the potentiometric method. The general order of magnitude for TBN is ... 

Conductometric Method of Analysis of Nitric-Sulfuric Acid Mixtures. See Y. Lacroix M. Chaverou, MP 41, 423-39 (1 959)... 

A variety of diorgano tellurium dihalides were shown by dielectrometric, cryoscopic, and conductometric methods to form 1 1 and 1 3 adducts with antimony pentachloridc in benzene solutions7. 

Film thickness of large bubbles can be evaluated with a conductometrical method [131]. If the electrodes are placed at the opposite poles of the bubble and the film thickness is uniform, then... 

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