Bicarbonate 304 INDEX

Bromine (128 g., 0.80 mole) is added dropwise to the well-stirred mixture over a period of 40 minutes (Note 4). After all the bromine has been added, the molten mixture is stirred at 80-85° on a steam bath for 1 hour, or until it solidifies if that happens first (Note 5). The complex is added in portions to a well-stirred mixture of 1.3 1. of cracked ice and 100 ml. of concentrated hydrochloric acid in a 2-1. beaker (Note 6). Part of the cold aqueous layer is added to the reaction flask to decompose whatever part of the reaction mixture remains there, and the resulting mixture is added to the beaker. The dark oil that settles out is extracted from the mixture with four 150-ml. portions of ether. The extracts are combined, washed consecutively with 100 ml. of water and 100 ml. of 5% aqueous sodium bicarbonate solution, dried with anhydrous sodium sulfate, and transferred to a short-necked distillation flask. The ether is removed by distillation at atmospheric pressure, and crude 3-bromo-acetophenone is stripped from a few grams of heavy dark residue by distillation at reduced pressure. The colorless distillate is carefully fractionated in a column 20 cm. long and 1.5 cm. in diameter that is filled with Carborundum or Heli-Pak filling. 4 hc combined middle fractions of constant refractive index are taken as 3-l)romoaccto])lu iu)nc weight, 94 -100 g. (70-75%) l).p. 75 76°/0.5 mm. tif 1.57,38 1.5742 m.]). 7 8° (Notes 7 and 8). 

Natural azurite is blue monoclinic crystal density 3.88 g/cm refractive index 1.730 decomposes at 220°C insoluble in cold water decomposes in hot water soluble in ammonium hydroxide and hot sodium bicarbonate solutions. 

In principle, it would be logical to combine plots of the buffer index curves of each of the buffer components of milk and thus obtain a plot which could be compared with that actually found for milk. It is not difficult, of course, to conclude that the principal buffer components are phosphate, citrate, bicarbonate, and proteins, but quantitative assignment of the buffer capacity to these components proves to be rather difficult. This problem arises primarily from the presence of calcium and magnesium in the system. These alkaline earths are present as free ions as soluble, undissociated complexes with phosphates, citrate, and casein and as colloidal phosphates associated with casein. Thus precise definition of the ionic equilibria in milk becomes rather complicated. It is difficult to obtain ratios for the various physical states of some of the components, even in simple systems. Some concentrations must be calculated from the dissociation constants, whose... 

The numbers listed were derived from the inhibition index values given by Ukita et al. (454)- The substrate was cy tidine 2 3 -phosphate, 8.8 mM. The Michaelis constant was reported to be 24 mM in the bicarbonate buffer 0.03 M, pH 7.6, 37°, that was used in all of the measurements. The inhibition constants were derived on the assumption of competitive inhibition in all cases. This type of inhibition was specifically shown for those compounds with a second number in parentheses. This latter number was obtained from multipoint double reciprocal plots in the usual manner. The agreement of the two... 

Figure 5.5 Langeleir Saturation Index (LSI) as a function of module position and recovery for a two-stage, 75%-recovery RO system. Assumes feed water conditions 200 ppm calcium, 150 ppm bicarbonate, and pH = 7.0.

The program calculates total dissolved solids (TDS), conductivity, and the Langelier and Stiff-Davis Saturation Indexes (see Chapter 3.9). The screen allows the designer to use sodium, calcium, magnesium, chloride, sulfate, or bicarbonate to balance the water analysis. Water quality for up to five feed streams can be entered and blended together to make the total, combined feed water to the system. 

Fig. 11. Calcite saturation index vs depth for Crooks Gap. The water analysis used for the calculations was the original water analysis plus the amount of added calcium and bicarbonate determined from Fig. 7.

The potential for well-bore scale during these CO2 treatments is determined by first predicting how much carbonate mineral dissolution will take place. After a calcite saturation index has been calculated for a water analysis for both pre- and post-C02 treatment, then Fig. 7 can be used to determine how much calcium (and therefore bicarbonate) will have been added to treated waters from calcite dissolution. These calcium and bicarbonate values can be added to the original formation water, which is then used to calculate a new calcite saturation index for the new water. 

Several workers have characterized the bicarbonate levels of waters with the Lange-lier Index (LI) ... 

Of course natural solutions, such as seawater, are not necessarily at equilibrium. In Figure 16.2 we see a river carrying dissolved material, including calcium and carbonate ions, entering the sea. Carbonate ions are already there, because the sea is in contact with the atmosphere, which contains carbon dioxide, and when CO2 dissolves it produces carbonate and bicarbonate ions. Because calcium and carbonate are being added, there may be a tendency for them to increase beyond the equilibrium value, and for calcite to precipitate as a result. The product of the calcium and carbonate ion activities which are actually present in a solution, regardless of any theory, is called the ion activity product (lAP) for that solution. It follows that when lAP > K, calcite will precipitate, and when lAP < calcite will dissolve. The lAP/ Tsp ratio is called O, and the logarithm of the ratio is called the saturation index (SI), so that when SI > 0 calcite precipitates, and when SI < 0 calcite dissolves (Table 16.1). 

The Larson-Shold index is based upon evaluation of in situ corrosion of mild steel lines transporting Great Lakes waters. Extrapolation to other waters than the Great Lakes, such as those of low alkalinity or extreme alkalinity, goes beyond the range of the original data. The index is the ratio of equivalents per million (epm) of sulfate (SO ) and chloride (Cl") to the epm of alkalinity in the form bicarbonate plus carbonate ... 

Zinc carbonate is a white material with composition ZnCOj which occurs in nature as the mineral smithsonite (q.v). It is Hsted in the Colour Index (1971) as Cl 77950, where it is described as synthesised by precipitating a zinc salt with sodium bicarbonate and as used in the USA as a white pigment (Merck Index, 1996). As mentioned by Kiihn (1986), zinc carbonate was used with copper as a starting material in the manufacture of brass in ancient times from which the by-product of white zinc oxide (q.v.) was first produced. Zinc carbonate may also form as an alteration product of zinc oxide in a humid environment. 

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