Carbon equivalent weight

Heat reagent-grade material for 1 hr at 255-265°C. Cool in an efficient desiccator. Titrate sample with acid to pH 4-5 (first green tint of bromocresol green), boil the solution to eliminate the carbon dioxide, cool, and again titrate to pH 4-5. Equivalent weight is one-half the formula weight. 

If 3 X kg of CO9 are cycled through the biosphere annually, how many human equivalents (70-kg persons composed of 18% carbon by weight) could be produced each year from this amount of CO9 ... 

Equivalent weight or gram equivalent, a mole divided by the valency of the substance. Example a mole of sodium chloride — 58.45 g, valency = 1, therefore equiv. wt = 58.45. A mole of calcium carbonate = 100.08 g, valency = 2, therefore equiv. wt. = 50.04. 

Alkalinity measurement is also required for the determination of active matter by difference and equivalent weight calculations. It can be determined as two of the following compounds sodium bicarbonate, sodium carbonate, or sodium hydroxide. The sample is titrated to a phenolphthalein endpoint to determine the sodium hydroxide/sodium carbonate content. An added measure of acid converts any bicarbonate to carbon dioxide, which is subsequently removed from the solution. Back-titration of the excess acid gives a measure of the amount of bicarbonate and/or carbonate present. 

Turning to the substrate balance, yeast cells contain about 50% carbon. The cell mass is measured as total dry weight, not just carbon. This gives Yx/s = 2 when S is measured as the carbon equivalent of glucose. A reasonable value for Yxis is 1 so that half the carbon goes into biomass and half meets the associated energy requirements. The maintenance coefficient in carbon-equivalent units is 0.008 h . Using these parameter estimates, the three simultaneous ODEs for 5" > 0, become... 

A considerable decrease in platinum consumption without performance loss was attained when a certain amount (30 to 40% by mass) of the proton-conducting polymer was introduced into the catalytically active layer of the electrode. To this end a mixture of platinized carbon black and a solution of (low-equivalent-weight ionomeric ) Nafion is homogenized by ultrasonic treatment, applied to the diffusion layer, and freed of its solvent by exposure to a temperature of about 100°C. The part of the catalyst s surface area that is in contact with the electrolyte (which in the case of solid electrolytes is always quite small) increases considerably, due to the ionomer present in the active layer. 

Thus, the equivalent weight of sodium carbonate may be equal to either the formula weight divided by 1 (105.99 g per equivalent, Equation (4.6)) or the formula weight divided by 2 (52.995 g per equivalent, Equation (4.7)), depending on which reaction is involved. 

As stated above, the equivalent weight of sodium carbonate as used in Equation (4.7) is the formula weight divided by 2 because it accepted two hydrogens in the reaction. Thus, utilizing Equation (4.3), we have the following ... 

There are two hydrogens accepted by sodium carbonate, so the equivalent weight is the formula weight divided by two, or 52.995 g per equivalent. Thus we have... 

Hundsdieke reaction org chem Production of an alkyl halide by boiling a silver carboxylate with an equivalent weight of bromine in carbon tetrachloride. honz.dek-o re,ak-sh3n ... 

Arfwedson prepared lithium acetate, ignited it, and noted the insolubility of the resulting lithium carbonate in water and its action on platinum. He also prepared and studied the bicarbonate, sulfate, nitrate, chloride, tartrate, borate, hydroxide, and a double sulfate which he reported as lithium alum. He mentioned that lithium hydroxide is much less soluble than the other caustic alkalies and that it has a greater saturation capacity [lower equivalent weight] than they. Because of its ability to form deliquescent salts with nitric and hydrochloric acids, Arfwedson recognized the close relation between the new alkali and the alkaline earths, especially magnesia. 

Carbon dioxide, 184, 358, 359 solid see Dry Ice Carbon disulphide, 767 purification of, 175 Carbon monoxide, 185, 1003, 1004 Carbon, decolourising, 127, 128 Carbon tetrachloride, 733, 815 drying of, 734 purification of, 176 Carbonyl chloride, 185 Carborundum chips, 4 Carboxylic acids, equivalent weights of, 1071 ... 

Citrate of Magnesia.—This is prepared by saturating a solution of citric aeid with carbonate of magnesia. It is a whito pulverulent insipid Salt, very soft to the touch, heavier than magnesia, and when a slight excess of citric acid is present, is dissolved readily by water. Its composition is—3 MgO, Ci, HO, or 3 MgO, H4 0, HO equivalent weight, 234. 

Compounds with carbon of compositions CS2, CSSe, CSe2, CSTe and CTe2 are known, as also arc series of salts of the type MCNX, M representing the equivalent weight of a metal, and X sulphur, selenium or tellurium. The tellurium compounds of the latter class are unstable. 

The first enzyme that was demonstrated to contain nickel was urease (urea amidohydrolase) from jack bean. It catalyzes the hydrolysis of urea to ammonia and carbon dioxide. The protein has a multimeric structure with a relative molecular mass of 590,000 Da. Analysis indicated 12 nickel atoms/mol. Binding studies with the inhibitors indicated an equivalent weight per active site of 105,000, corresponding to 2 nickel atoms/active site. During removal of the metal by treatment with EDTA at pH 3.7, the optical absorption and enzymatic activity correlated with nickel content. This, combined with the sensitivity of the enzyme to the chelating agents acetohydroxamic acid and phos-phoramidate, indicates that nickel is essential to the activity of the enzyme (1). 

Philadelphia. This polymers, structurally a straight carbon skeleton with ester side chains, the esters being from quaternary ammonium substituted alcohols, are soluble in water, and the water solution has a viscosity of 2500 to 5000 centipoises in 5% aqueous solution at room temperature. Equivalent weight of the polymers based on the ammonium groups, are about 350-360 2)... 

Figure 1.11, prepared by the U.S. Energy Information Administration, describes the global carbon cycle. It provides data that was collected in 2001. Since that date, the yearly anthropogenic carbon emissions (measured in carbon equivalent terms) increased from 6.3 to about 9 billion metric tons (over 1 ton per capita in the world). In November 2007, the National Academy of Science reported actual emissions for 2006 as 8.4 billion tons. Carbon equivalent means that the emission of 3.7 tons of COz is counted as the emission of 1 ton of carbon, so the 8.4 billion tons per year of carbon that enters the atmosphere owing to fossil fuel combustion corresponds to 33 billion tons per year of C02 because of the molecular weight ratio of COz to carbon (44/12). 

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