Water estimations, uncertainties

A standard solution of Mn + was prepared by dissolving 0.250 g of Mn in 10 ml of concentrated HNO3 (measured with a graduated cylinder). The resulting solution was quantitatively transferred to a 100-mL volumetric flask and diluted to volume with distilled water. A 10-mL aliquot of the solution was pipeted into a 500-mL volumetric flask and diluted to volume, (a) Express the concentration of Mn in parts per million, and estimate uncertainty by a propagation of uncertainty calculation, (b) Would the uncertainty in the solution s concentration be improved... 

A major source of error in most measurements is the presence of impurities in the sample. The effect of an impurity depends upon its amount in the sample and upon the difference between its density and the density of the principal constituent. Even when the sample purity is provided quantitatively, the impurities often are not identified individually. Nevertheless, a report of sample purity reduces the estimated uncertainty because it can be taken as evidence that the investigator has considered sample purity. The most ubiquitous impurity in liquids is water, and, because its density differs significantly from those of hydrocarbons, it is a common source of error. Exclusion of water requires that the sample be protected from the atmosphere during transfer, and that special precautions be taken to remove the sample from containers. 

One set of aluminosilicate equilibrium relationships for which some quantitative data are available is depicted in Figure 5. This figure (25° C) is derived from information presented and discussed by Hemley (15), Feth, Roberson, and Polzer (8), and Garrels and Christ (11). The dual boundaries between potassium mica (muscovite) and kaolinite reflect the roughly estimated uncertainty in the equilibrium constant. The relationship of this boundary to actual K -H+ ratios in sea water may be... 

The solubility of CO in water, expressed as mole fraction of CO in the liquid phase, is given for pressures up to atmospheric and temperatures of 0 to 100 °C. Note that 1 standard atmosphere equals 101.325 kPa. The references give data over a wider range of temperature and pressure. The estimated uncertainty is about 2%. 

The experimental and UNIQUAC LLE data for (water + propionic acid + 1-octanol) at different temperature of (293.15-303.15) K, are presented in Table 14.1. The estimated uncertainties in the mole fraction were about 0.0005. From the LLE phase diagrams (Figure 14.1-14.4), (1-octanol + water) mixture is the only pair that is partially miscible and two liquid pairs (propionic acid + water) and (propionic acid + 1-octanol) are completely miscible. The mutual solubility of 1-octanol and water is very low and therefore, the high boiling point solveni (1-octanol) can be used as a rehable oiganic solvent for extraction of prpionic acid from dilute aqueous solutions. 

The resulting A(G°° (I, W S) values on the M-scale for the transfer of numerous ions from water to non-aqueous solvents at 25°C are shown in Table 4.2, adapted from Refs. 31-35. Values shown to one decimal have an estimated uncertainty of 0.5kJ mol" , those shown as integral values have an estimated uncertainty of 2.0kJ mol" , and those shown in bold font have been more recently recommended [34,35] as the most probably correct values. The uncertainties of the latter values are derived from independent determinations of the AjG (P, W -> S) values by several authors and are understood to be beyond the uncertainty due to the preferred extra-thermodynamic assumption dealt with in the previous paragraph. 

The stracture of the complex is similar to that of water dimer. Uncertainties were not estimated in the original paper. 

The expressions are valid over the temperature range 200-350 K for air diluent. The coefficients kj, and 2 are the termolecular and high-pressure limit for the association channel, respectively. At 298 K, the recommended rate coefficient value is = 1.5 x 10 molecule cm s with an estimated uncertainty of 10% (lUPAC, 2008). Carl et al. (2001) have shown that the water vapor does not affect the rate coefficient under atmospheric conditions. 

The number of injectors required may be estimated in a similar manner, but it is unlikely that the exploration and appraisal activities will have included injectivity tests, of say water injection into the water column of the reservoir. In this case, an estimate must be made of the injection potential, based on an assessment of reservoir quality in the water column, which may be reduced by the effects of compaction and diagenesis. Development plans based on water injection or natural aquifer drive often suffer from lack of data from the water bearing part of the reservoir, since appraisal activity to establish the reservoir properties in the water column is frequently overlooked. In the absence of any data, a range of assumptions of injectivity should be generated, to yield a range of number of wells required. If this range introduces large uncertainties into the development plan, then appraisal effort to reduce this uncertainty may be justified. 

However, the significance of results from such analyses depends on the quality of the input data. For example, laboratory recipes often do not meticulously document solvent and auxiliary input masses. In many cases, water inputs and waste management are not determined before the pilot stage is reached. Estimates similar to those applied in LCA may be used in order to complete a preliminary mass balance. While such estimations cause considerable uncertainty, it seems more appropriate to evaluate alternatives based on preliminary information, that is, experience-based assumptions concerning the production of substrate or catalyst, than to simply ignore potentially important contributions to the mass balance. 

Because of uncertainties of equilibrium constants, ES, pH, temperature, /02 and other parameters (activity coefficient, ionic strength, activity of water, pressure), the estimated values of concentrations may have uncertainties of 1 in logarithmic unit. However, it can be concluded from the thermochemical calculations and fluid inclusion data that the Kuroko ore fluids have the following chemical features. 

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