Bicarbonate diagram

In a similar feshion, fi. n-pH diagrams can be constructed for other redox half reactions. Some examples are given in Figure 7.8. These diagrams suggest that in oxic seawater = +0.4 V and pH = 8), the stable form of iron is Fe(OH)3, nitrogen is stable as nitrate, sulfur as sulfete, and carbon as bicarbonate, if each of these species reaches redox equilibrivun. 

This process can be illustrated by connecting an apparatus, A, for generating ammonia, Fig. 65, and an apparatus, B, for making washed carbon dioxide with a tower, O, filled with a sat. soln. of sodium chloride and fitted with four perforated iron discs as shown in the diagram. The tower is provided with an exit tube dipping in a beaker of water. The soln. is first sat. with ammonia, and then with carbon dioxide. In about an hour, crystals of sodium bicarbonate will be deposited on the perforated shelves. 

Figure 9. Bubble diagram of concentrations (milligrams per liter) of chemical components and pH in well 138 (Figure 3) showing changes with time in wells of different depths the upper scale bar (bubble diameter) is the concentration of the species as depicted by bubble, the vertical axis is the elevation of the screened interval of the well, and the horizontal axis is the days since drawdown A, bicarbonate and B, calcium.

Figure 7. Flow diagram of sea water demineralization by ammonium bicarbonate...

Figure 3. A schematic diagram of the renal proximal tubule showing how the Na+/H+ exchanger, by acidifying tubular fluids, promotes the regeneration of bicarbonate. Interconversions of C02, water, H+, OH and HCOj are catalyzed by carbonic anhydrase (membrane bound and cytosolic).

Weathering of continental rocks increases their TDS and concentrations of calcium and bicarbonate relative to sodium and chloride. The composition of streams so affected plot to the left of both diagrams and include the Columbia, Mississippi, Yukon, and Thames rivers. Evaportranspiration from arid climate drainage basins and streams such as the Colorado, Pecos, and Jordan rivers, which receive soil runoff and irrigation return waters, further increase the Na and TDS content of streams. Concomitant precipitation of CaC03 further shifts the prevalent chemical character of such streams back toward NaCl and the chemistry of seawater. 

Figure 12.10 Eh-pH diagram for the system Fe-02-C02-H20 at 25 C ignoring ferrosic hydroxide [Fc3(OH)g] and assuming = 37.1 for amorphous Fe(OH>3. Bicarbonate is fixed at 10 mol/kg. Aqueous/solid boundaries are drawn for total dissolved iron concentrations of 10 mol/kg (solid line) and ICF mol/kg (heavy dashed line). Lightly dashed lines show the positions of the aqueous/aqueous species boundaries identified in Fig. 12.8.

Standard aqueous electrode potentials for reactions involving carbon have been calculated from the free energy of formation of carbon-containing compounds at different pH and temperature[3-6]. These data, displayed as potential-pH equilibrium diagrams, determine the domains of relative predominance of carbon as such or under a dissolved carbon-containing species such as methanol, aldehyde, acetic acid, carbonate, bicarbonate, or gaseous species such as methane, carbon dioxide, and carbon monoxide. 

Fig. 11. Diagram illustrating the comparison between carbon isotopic composition of authigenic calcites and the bicarbonates of modem formation waters from the Swiss Molasse basin.

Under the conditions of experiment (temperature = 15 ) sodium chloride and ammonium bicarbonate cannot coexist in contact with solution. These determinations gave the data necessary for the construction of the complete isothermal diagram (Fig. 153). For the sake of comparison, the results are also represented in the quadrangular diagram of Janecke (Fig. 154). The most important of these data are given in the following table (temperature 15 ) —... 

Figure 9. Diagram summarizing the isotopic relationships between dissolved CO2, bicarbonate, and the carbon added to phosphoenolpyravate in order to produce C-4 in oxaloacetate.

Figure 17. Diagram summarizing isotopic relationships between inorganic carbon pools and carbon in photosynthate and C4 carbon skeletons, is the equilibrium isotopic fractionation between dissolved CO2 and bicarbonate (Mook et al. 1974). is the isotope effect associated with carbon fixation. The estimate of d for internal CO2 is based on = -25%o and % = 27%o. is the isotope effect associated with phosphenolpymvate carboxylase (O Leary et al. 1982). The carbon pools represented in the right-hand colurrm are, from top to bottom, the carbon added by the carboxylation of phosphoenolpymvate, the total carbon in aspartic acid and in oxaloacetate, and the total carbon in pyravate.

The problem therefore becomes one of a mixture of 3 constituents that can each theoretically vary between 0 and 82.42% of the tablet mass the saccharose, citric acid plus bicarbonate, and the sorbitol. The experimental domain may be represented by the ternary diagram of figure 3.7a. 

DIRECTIONS (Items 17-20) The diagram below shows some of the steps involved in the reabsorption of bicarbonate. For each of the numbered items in the diagram, identify the substance denoted. 

Figure 8 Conceptual diagram of a simplified carbonate pump . Some marine organisms form calcareous skeletal material, a portion of which sinks as calcium carbonate aggregates. These aggregates are preserved in shallow ocean sediments or dissolve at greater depths (3000-5000 m), thus increasing DIG concentrations in the deep ocean. The calcium and bicarbonate are returned to the surface ocean through upwelling.

The only aqueous species of significance in Figure 1 below pH 10 is the Mn ion. Hydroxide complexes are considered at higher pH s. Organic complexes of Mn may be significant in some natural systems, but are not considered in this diagram. Bicarbonate and sulfate complex stabilities are given elsewhere (14). 

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