Acidic primaries, zinc electrodes

It is so universally applied that it may be found in combination with metal oxide cathodes (e.g., HgO, AgO, NiOOH, Mn02), with catalytically active oxygen electrodes, and with inert cathodes using aqueous halide or ferricyanide solutions as active materials ("zinc-flow" or "redox" batteries). The cell (battery) sizes vary from small button cells for hearing aids or watches up to kilowatt-hour modules for electric vehicles (electrotraction). Primary and storage batteries exist in all categories except that of flow-batteries, where only storage types are found. Acidic, neutral, and alkaline electrolytes are used as well. The (simplified) half-cell reaction for the zinc electrode is the same in all electrolytes ... 

Danlell cell physchem A primary cell with a constant electromotive force of 1.1 volts, having a copper electrode in a copper sulfate solution and a zinc electrode in dilute sulfuric acid or zinc sulfate, the solutions separated by a porous partition or by gravity. dan-yol, sel )... 

As already stated, the measured electromotive force of a galvanic cell does not necessarily correspond to a single definite reaction. For example, a powerful primary cell may be constructed by placing a porous cup containing a platinum or carbon electrode, surrounded by nitric acid, into another vessel containing an amalgamated zinc electrode in an electrolyte of sulphuric acid. This cell may be represented by... 

Daniell cell /dan-yel/ A type of primary cell consisting of two electrodes in different electrolytes separated by a porous partition. The positive eletrode is copper immersed in copper(II) sulfate solution. The negative electrode is zinc-mercury amalgam in either dilute sulfuric acid or zinc sulfate solution. The porous pot prevents mixing of the electrolytes, but allows ions to pass. With sulfuric acid the e.m.f. is... 

Daniell cell A type of primary voltaic cell with a copper positive electrode and a negative electrode of a zinc amalgam. The zinc-amalgam electrode is placed in an electrolyte of dilute sulphuric acid or zinc sulphate solution in a porous pot, which stands in a solution of copper sulphate in which the copper electrode is immersed. While the reaction takes place ions move through the porous pot, but when it is not in use the cell should be dismantled to prevent the diffusion of one electrolyte into the other. The e.m.f. of the cell is 1.08 volts with sulphmic acid and 1.10 volts with zinc sulphate. It was invented in 1836 by the British chemist John Daniell (1790-1845). 

Bunsen cell A type of primary cell in which the positive electrode is formed by carbon plates in a nitric acid solution and the negative electrode consists of zinc plates in sulfuric acid solution. 

The Zn negative electrode material, or anode, and electrolyte solution are similar to other primary alkaline battery types, like zinc-air and zinc-silver oxide (Zn/ Ag20). Zinc powder is mixed with a gelling agent like polyacrylic acid and a KOH-Zn0-H20 electrolyte. 

Danicll cell A primary cell where a zinc rod (the negative electrode) is immersed in a saturated solution of either zinc sulfate or dilute sulfuric acid contained within a porous pot. This pot is immersed in a solution of copper(II) sulfate, contained in a copper vessel, which forms the positive electrode. The cell produces an e.m.f. of 1.1 volts. 

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