Gram-equivalent weight

The number of grams in a sample divided by the number of equivalents in the same sample gives the gram-equivalent weight of the material. 

Faraday s law states that 96,487 coulombs (1 C = 1 A-s) are required to produce one gram equivalent weight of the electrochemical reaction product. This relationship determines the minimum energy requirement for chlorine and caustic production in terms of kiloampere hours per ton of CI2 or NaOH... 

Faraday s Law of electrolysis states that the amount of chemical change, ie, amount dissolved or deposited, produced by an electric current is proportional to the quantity of electricity passed, as measured in coulombs and that the amounts of different materials deposited or dissolved by the same quantity of electricity are proportional to their gram-equivalent weights (GEW) defined as the atomic weight divided by the valence. The weight in grams of material deposited, IF, is given by... 

Cathode Efficiency. Faraday s law relates the passage of current to the amount of a particular metal being deposited ie, 96,485 coulombs, equal to one Faraday, deposits one gram-equivalent weight of a metal at 100% efficiency. The cathode efficiency, an important factor in commercial electroplating, is the ratio of the actual amount of metal deposited to that theoretically calculated multipHed by 100%. 

It may be pointed out that for uni-univalent electrolytes the values of a and am are identical since the gram equivalent weight and the gram molecular weight are the same. In the case of uni-bivalent and bi-univalent electrolytes the a value is half the am value since the equivalent weight of such compounds is half the molecular weight. 

If the resistance of any other electrolyte is found by measurement to be Rx when using the same conductance cell, then the specific conductance of this electrolyte is L1/ . Thus, on multiplying the value of specific conductance so obtained by V, the volume of solution in milliliters containing one gram equivalent weight of the electrolyte under investigation, the equivalent conductance A is calculated. 

The gram-equivalent weight (GEW) of a base is the mass of the base (in grams) that will provide 1 mole of hydroxide ions in a reaction or that will react with 1 mole of H+ ions. This problem can be done by using the factor-label method. 

The concentrations of electrolyte solutions are generally expressed in chemical units known as milliequivalents (mEq). The milliequivalent weight represents the amount, in milligrams, of a solute equal to 1/1000 of its gram equivalent weight. A milliequivalent is a unit of measurement of the amount of chemical activity of an electrolyte. A milliequivalent unit is related to the total number of ionic charges in solution and it takes the valence of the ions into consideration. Table 5.1 provides valence, atomic and milliequivalent weights, and formulae of selected ions. 

N(normal). The abbreviation and term used to describe a solution containing a gram equivalent weight of reactive material per liter of solution. 

The quantity of electricity required to produce a gram-equivalent weight of chemical change is known as the faruday. A faraday corresponds, then, to an Aengadro number of charges. The most accurate determination of the... 

As an example, the chlorine atom of potassium chloride (KCl) also is found in hydrochloric acid (HC1) in combination with one hydrogen atom, Thus, the gram-equivalent weight of KCl is 74.555, which is the same as its gram-molecular weight. A one normal solution of KCl will contain 74.555 grams of the salt per liter of solution. 

If one gram equivalent weight of iodine reacts with one gram equivalent weight (or 1000 mg equivalent weight) of the analyte present in a measured volume of sample, the concentration of analyte, as mg/L analyte... 

Electrochemical equivalent. The electrochemical equivalent of any substance is that quantity which is liberated by the passage of 1 C of electricity. It has already been shown that 1 C is required for the deposition of 0.001118 g of silver hence, 0.001, 118, or 1.118 x 10 3 g, is the electrochemical equivalent. Similarly, 1 F of electricity liberates 1 gram-equivalent weight of copper (31.785 g) the electrochemical equivalent of copper is therefore 31.785/96,500 = 3.294 x 10 4 g, and the electrochemical equivalent of bismuth or any other element may be calculated in an entirely analogous manner. 

CaCl2 shows that the gram equivalent weight is or 37... 

The gram equivalent weight of salts is obtained in the same way. In the two neutralization reactions mentioned above, one mole of NaCl and one-half mole of CaCU are each equivalent to one mole... 

Theoretical capacity — A calculated amount of electricity (-> charge) involved in a specific electrochemical reaction (expressed for -> battery -> discharge), and usually expressed in terms of -> ampere-hours per kg or -> coulombs per kg. The theoretical capacity for one gram-equivalent weight of material amounts to 96,487 C (see -> Faraday constant) or 26.8 Ah. The general expression for the calculation of the theoretical capacity (in Ah kg-1) for a given -> anode material and - cathode material and their combination as full cell is given by... 

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