Vessel electrolysis

The electrolysis vessel usually consists of a tall form beaker without a lip the outer electrode should fit easily into the beaker, but the volume of liquid between electrode and beaker should be kept as small as possible. To prevent loss by spray, the beaker should be covered by a watchglass this should be drilled to accommodate the electrode connections, and then split into two. 

The mercury at the bottom of the electrolysis vessel must be carefully... 

Reductions were carried out in the electrolysis vessel shown in Figure 1. One reduction (No. 14) was carried out in a divided cell provided with a... 

A 1.0 molar solution of copper sulfate is electrolyzed with an inert, e.g., platinum, anode and a copper cathode of 55 sq. cm. exposed area the current is maintained constant at 0.040 amp. If the electrolysis vessel contains 1 liter of solution and there is reasonable circulation of the electrolyte, without resort to stirring, estimate approximately how long electrolysis will proceed before hydrogen evolution commences. How much of the original copper will then have been deposited ... 

The copper can be purified by electrolysis to 99.95 percent purity. The large blocks of blister copper are used as anodes suspended in a solution of aqueous copper(II) sulfate. Pure copper is used as the cathode. During electrolysis, copper is oxidized at the anode, moves through the solution as Cu + ions, and is deposited on the cathode. Waste products left after the dissolution of the anode produce a sludge on the bottom of the electrolysis vessel. The sludge, which is often rich in silver and gold, can be recovered for profit. 

A platinum dish serves as the electrolysis vessel and the cathode. It is placed on a water bath at 50°C. A 100-g. solid Ag bar with a welded-on Ag lead wire is used as the anode. The maximum current density of the cathode is 0.002 amp./cnaj The volt e drop across the electrodes is 1.4 v. A 6-v. battery is used as the power supply the current is 0.07-0.1 amp. 

A 500-ml. battery jar, placed in a lai er container which has an inlet and an outlet for cooling water, is used as the electrolysis vessel. The 1.4 X 4 cm. anode, a shiny Pt sheet, is suspended in the middle. Two Pt wire-gauze cathodes havii over-all surface areas of 15 cm. each are attached parallel to the anode, one on either side. The cathode-anode distance is 1.5 cm. 

Pure Li is prepared (via the method of Ruff and Johannsen) from LiBr which is melted in an electric arc in the presence of 10-15% LiCl (the LiBr is obtained from LigCOs by evaporating the latter from hydrobromic acid). Fig. 260 is a scale drawing (1 5) of the Muthmann electrolysis vessel used for the melting procedure. It is made of copper and its upper part is cooled with water. While... 

Fig. 260. Electrolytic preparation of lithium. The electrolysis vessel, made of copper, has a diameter of about 8 cm. at the top and about 2.5 cm. at the bottom.

A cylindrical graphite crucible serves both as the electrolysis vessel and as anode. The inside diameter is 6 cm. and the height 15 cm., with a wall thickness of 1-2 cm. Current is supplied through a strip of Ni sheet wrapped around the upper part of the outside wall. The cathode is a strip of Mo sheet 0.05 mm. thick and 1 cm. wide, which reaches 2.5 cm. from the bottom. The graphite cell stands in a suitable refractory container wound with the heating filament. The entire apparatus is placed inside a sheet-metal vessel filled with thermal insulation (see also the similar arrangement described for the electrolysis of uranium). 

A low vertical cylinder closed off with a rubber stopper serves as the electrolysis vessel and contains the sulfate solution. The anode is a piece of Pt sheet immersed in a clay cell filled with 20% H3SO4. The cell is partially immersed in the Ti (TV) sulfate solution and is surrounded by four amalgamated lead strips, also immersed in the solution. The stopper on the outer electrolysis vessel has holes for the clay cell and for the inlet and outlet gas tubes. The electrolysis is carried out in a constant stream of COg and with efficient water cooling. The current density is 0.06 amp./cm. at 24 v. for the first six hours, then 0.33 amp./cm. at the same voltage for an additional six hours. This reduces all the Ti (IV) sulfate to Ti (III) sulfate the latter precipitates as an H3804-containing hydrate (fine, pale light violet crystals). 

The electrolysis vessel consists of a glass cylinder, 5 cm. in diameter and 10 cm. high, such as, for example, a small Pyrex pressure vessel. This vessel is closed with a five-hole rubber stopper to accommodate the cathode stem, thermometer, diaphragm, and Ng inlet and outlet tubes. A suitable outlet tube is a small fermentation tube, which serves as protection against air and should, if possible, be drawn out into an outward-pointing capillary. 

A solution of 20 g. of H3M0O4 H3O in 150 ml. of cone. HCl and 50 ml. of distilled water is electrolyzed for several hours at about 0.06-0.12 amp./in. the electrolysis vessel is water cooled and CO3 is bubbled through the solution. The solution is thus reduced to the red, trivalent state. 

Objects to be plated with platinum (cathodes) are prepared in exactly the same way as in any other method of electroplating. Given the cost of platinum, these objects are usually small platinum electrolysis vessels therefore need to hold only a few liters of the solution the vessel will thus usually be a glass or porcelain beaker or a small iron trough coated on the inside with a special alkali- and acid-resistant enamel. If the platinum deposit is too dull, it can be rubbed and scoured in the same way as gilt-ware, and then replaced in the platinum bath to deposit a further platinum layer this treatment may be repeated imtil the required deposit thickness is reached. 

Briefly, in ECP two or three electrodes are mounted in an electrolysis vessel containing solvent with dissolved electrolyte and monomer. As current flows the polymer is deposited on the anode as a continuously thickening layer. After a certain time the current is switched off and either the whole anode with its polymer-covered layer is used for characterization procedures, or, if the polymer is not too brittle, the layer is peeled off from the anode surfaces and used as a self-supporting film. 

T, Awakura Y (2006) Galvanic contact deposition of CdTe frran ammoniacal basic electrolytes at elevated temperatures using an autoclave-type electrolysis vessel. Electrochem Commun 8 605... 

Fig. 1. Schematical view of polarographic circuit. (C) capillary of the mercury dropping electrode (V) electrolysis vessel (S) solution to be analysed (R) reference electrode (Nj) nitrogen inlet and outlet (M) mercury reservoir (G) galvanometer (DF) potentiometer ...

For measuring polarographic currents, an arrangement must be available consisting of a mercury dropping electrode (or another type of indicator electrode), a reference electrode, both placed in an electrolysis vessel containing the solution to be analysed, and a polarograph. 

ELECTROLYSIS VESSELS A great number of different vessels for general and special purposes are described in the polarographic literature. Some examples of simple vessels are given in this chapter. 

Add 0-4 ml. of the filtrate to 4 ml. of cobaltic solution, consisting of O OOl M Co(NH3),Cl3, 0-1 N ammonium chloride and 0-1 N ammonia. After mixing, transfer the solution to a simple electrolysis vessel (test tube) and polarograph the solution, open to the atmosphere, from —0 8 V against the mercury pool electrode. 

A completely different approach to establish a heated solution region is followed by two techniques which make use of an ordinary electrolysis vessel that is converted to give a non-isothermal cell just by generating a hot spot in close vicinity to the electrode-solution interface. The electrode material itself is not... 

A number of workers (30, 31) have described cells with external mercury reservoirs in the form of leveling bulbs to permit the introduction or withdrawal of the cathode material without introduction of air or other contaminants. Electrical contact may be maintained directly through the mercury or, if it is desired to have a stopcock between the reservoir and the electrolysis vessel, through a platinum contact sealed into the wall of the cell. 

The electrolysis vessel, C, la protected from mercury Ions diffusing from the working reference calomel electrode. A, by a medium glass frit between B and C, and a fine frit backed with an agar plug between B and A. Between runs, cell C is kept filled with saturated potassium chloride solution. 

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