One source datum

Several data available at different ionic strengths 

Data at non-standard conditions Procedures for data correction and recalculation. 

The assignment of an uncertainty to a selected value that is based on only one experimental source is a highly subjective procedure. In some cases, the number of data points the selected value is based on allows the use of the root mean square [82TAY] deviation of the data points Jf, to describe the standard deviation associated with the average X  

The standard deviation is thus calculated from the dispersion of the equally weighted data points Aj around the average X, and the probability is 95% that an Aj is within X + 1.96 sx, see Taylor [82TAY] (pp.244 - 245). The standard deviation is a measure of the precision of the experiment and does not include any systematic errors. 

Many authors report standard deviations Sx calculated with Eq. (C.4) (but often not multiplied by 1.96), but these do not represent the quality of the reported values in absolute terms. It is thus important not to confuse the standard deviation s with the uncertainty a. The latter reflects the reliability and reproducibility of an experimental value and also includes all kinds of systematic errors s, that may be involved. The uncertainty a can be calculated with Eq. (C.5), assuming that the systematic errors are independent. 

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One hundred pounds of a 73% NaOH solution at 350°F is to be diluted to give a 10% solution at 80°F. How many pounds of water at 80°F and ice at 32°F are required if there is no external source of cooling available See Fig. E4.43. Use the steam tables and the NaOH-HiO enthalpy-concentration chart in Appendix I as your source of data. (The reference conditions for the latter chart are AH = 0 at 32 for liquid water and AH = 0 for an infinitely dilute solution of NaOH, with pure caustic having an enthalpy at 68°F of 455 Btu/lb above this datum.)... 

The solubility datum at 362.8 K and 330 bar was corrected as it is one order of magnitude smaller in th source than the actual value in the Friedrich s thesis. Synonyms n-Octadecyl alcohol 1-Stearyl alcohol Source Friedrich, J. Schneider, G. M. J. Chem. Thermodyn. (1989), 21(3), 307-319. 

We would like to provide means of expressing as many different types and pieces of data as possible. For those attributes of molecules which admit numerical values (such as the solubility or the Gibbs energy), how do we handle conflicting data from different literature sources, and how do we keep track of the conditions and necessary qualifications of each datum We can provide the ability to store more than one value for each attribute, in the form of a list of data objects. The role of the datum object is to encapsulate all the bookkeeping and reference information accompanying a numerical value (Table 6). 

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