Electrodes antimony

Electrical units 503, 519 Electrification due to wiping 77 Electro-analysis see Electrolysis and Electrogravimetry Electrochemical series 63 Electro-deposition completeness of, 507 Electrode potentials 60 change of during titration, 360 Nernst equation of, 60 reversible, 63 standard 60, (T) 62 Electrode reactions 505 Electrodeless discharge lamps 790 Electrodes antimony, 555 auxiliary, 538, 545 bimetallic, 575... 

Electrochemical detection has been achieved in a number of ways. The change in pH has been sensed with a traditional glass pH electrode antimony electrode or amperometrically via the pH sensitive oxidation of hydrazine... 

Simultaneous and continuous measurements of extracellular pH, potassium K+, and lactate in an ischemic heart were carried out to study lactic acid production, intracellular acidification, and cellular K+ loss and their quantitative relationships [6, 7], The pH sensor was fabricated on a flexible kapton substrate and the pH sensitive iridium oxide layer was electrodeposited on a planar platinum electrode. Antimony-based pH electrodes have also been used for the measurement of myocardial pH in addition to their application in esophageal acid reflux detection. 

Adrenaline Glucose dehydrogenase/laccase Oxygen electrode antimony pH... 

M. Maja and N.Penazzi [1985] Ac Behaviour of Lead Dioxide Electrode Antimony Effect., Electrochim. Acta 30, 773—778. 

Bromine has a lower electron affinity and electrode potential than chlorine but is still a very reactive element. It combines violently with alkali metals and reacts spontaneously with phosphorus, arsenic and antimony. When heated it reacts with many other elements, including gold, but it does not attack platinum, and silver forms a protective film of silver bromide. Because of the strong oxidising properties, bromine, like fluorine and chlorine, tends to form compounds with the electropositive element in a high oxidation state. 

Anodic stripping voltammetry at a mercury film electrode can be used to determine whether an individual has recently fired a gun by looking for traces of antimony in residue collected from the individual s hands, fn a typical analysis a sample is collected with a cotton-tipped swab that had been wetted with 5% v/v HNO3. When returned to the lab, the swab is placed in a vial containing 5.00 mb of 4 M HCl that is 0.02 M in hydrazine sulfate. After allowing the swab to soak overnight,... 

Two methods are used to measure pH electrometric and chemical indicator (1 7). The most common is electrometric and uses the commercial pH meter with a glass electrode. This procedure is based on the measurement of the difference between the pH of an unknown or test solution and that of a standard solution. The instmment measures the emf developed between the glass electrode and a reference electrode of constant potential. The difference in emf when the electrodes are removed from the standard solution and placed in the test solution is converted to a difference in pH. Electrodes based on metal—metal oxides, eg, antimony—antimony oxide (see Antimony AND ANTIMONY ALLOYS Antimony COMPOUNDS), have also found use as pH sensors (8), especially for industrial appHcations where superior mechanical stabiUty is needed (see Sensors). However, because of the presence of the metallic element, these electrodes suffer from interferences by oxidation—reduction systems in the test solution. 

The standard electrode potential for zinc reduction (—0.763 V) is much more cathodic than the potential for hydrogen evolution, and the two reactions proceed simultaneously, thereby reducing the electrochemical yield of zinc. Current efficiencies slightly above 90% are achieved in modem plants by careful purification of the electrolyte to bring the concentration of the most harmful impurities, eg, germanium, arsenic, and antimony, down to ca 0.01 mg/L. Addition of organic surfactants (qv) like glue, improves the quaUty of the deposit and the current efficiency. 

In seawater, lead anodes with 1 or 2% silver may be used for cathodic protection of ships " at current densities of up to 120Am Lead with 6Vo antimony and 1 Vo silver has also been recommended. It is thought that silver might provide small stable nucleation sites for PbOj formation " in a manner similar to the Pb/Pt bi-electrode " (see Section 11.3), which is serviceable at 250 A m . A lead. Wo Ag, 0.5% Bi or 0.5% Te alloy with a platinum micro-electrode will perform well at 500 A m. ... 

Private Report on Films on Lead-Silver-Antimony Electrodes, Fulmer Research Institute to eWE Ltd. 

Anode Electrode at which oxidation occurs and toward which anions move, 481-485,496 Antifreeze solution, 270 Antimony, 63... 

Procedure. Place 45 mL of the supporting electrolyte in the cell and fill the isolated cathode compartment with the same solution to a level well above that in the cell. Pipette 5.00, 10.00, or 15.00 mL of the 0.01 M antimony solution into the cell and titrate coulometrically with a current of 40 milliamps. Stir the solution continuously by means of the magnetic stirrer and take e.m.f. readings of the Pt-S.C.E. electrode combination at suitable time intervals the readings may be somewhat erratic initially, but become steady and reproducible after about 3 minutes. Evaluate the end point of the titration from the graph of e.m.f. vs counter reading this shows a marked change of e.m.f. at the end point. If it proves difficult to locate the end point precisely, recourse may be made to the first- and second-differential plots. 

For some industrial operations an antimony electrode is used to measure hydrogen-ion concentrations. The electrode consists of a rod of antimony which invariably has a coating of oxide, and placed in an aqueous solution the equilibrium... 

As indicator electrodes glass and antimony electrodes are commonly used, but it must be noted that in benzene-methanol solutions, a glass-antimony electrode pair may be used in which the glass electrode functions as reference electrode. Glass electrodes should not be maintained in non-aqueous solvents for long periods, as the hydration layer of the glass bulb may be impaired and the electrode will then cease to function satisfactorily. 

Dilute solutions of antimony(III) and arsenic(III) (ca 0.0005M) may be titrated with standard 0.002 M potassium bromate in a supporting electrolyte of 1M hydrochloric acid containing 0.05 M potassium bromide. The two electrodes are a rotating platinum micro-electrode and an S.C.E. the former is polarised to +0.2 volt. A reversed L-type of titration graph is obtained. 

The above comparative evaluation of starter battery separators refers to moderate ambient temperatures the standard battery tests arc performed at 40 or 50 °C. What happens, however, on going to significantly higher temperatures, such as 60 or 75 °C This question cannot be answered without considering the alloys used batteries with antimonial alloys show a water consumption that rises steeply with increasing temperature [40], leaving as the only possibilities for such applications either the hybrid construction, i.c., positive electrode with low-antimony alloy, negative electrode lead-calcium, or even both... 

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