## 3 Results and Discussion
### Solute Fusion Parameters  
LAA is known to possess low thermal stability and to commence decomposing near the melting point [26; 27; 28; 29; 30]. Consequently, the assessment of fusion parameters is not only dependent on the measurement method, but also on experimental conditions, such as heating rates, causing discrepancies in the literature data, which should be used with due care. [PERSON] et al. [30] reference eight Differential Scanning Calorimetry (DSC) investigations, reporting melting points from 190.4 to 197.0 \({}^{\circ}\)C with a median of 192.9 \({}^{\circ}\)C. [PERSON] quoted fusion temperatures of 191 \({}^{\circ}\)C (Kofler bench), 185-190 \({}^{\circ}\)C (hot-stage microscope), 189-194 \({}^{\circ}\)C (capillary tube), and 188 \({}^{\circ}\)C (Differential Thermal Analysis, DTA) [31]. Error estimates for the melting temperature were attempted by the Thermodynamic Research Centre [32] using the NIST Thermodata Engine [12] and by the Design Institute for Physical Property Data [14], all aiming to provide comprehensive measures of the overall data reliability. These evaluated data for \(T_{m,1}\) are compiled in Table 3. Weighting these individual estimates with the reciprocal uncertainty yields a mean of 190.6 \({}^{\circ}\)C with a presumed most probable error of \(\pm 5\)\({}^{\circ}\)C. The latter value is justified by allowing for a safety margin in view of an average compound error of \(\pm 4.25\)\({}^{\circ}\)C, and an uncertainty of \(\pm 4\)\({}^{\circ}\)C (95% CI) for the most comprehensive error estimation published [12] (pp. 3-1, 3-30).  
Because LAA degradation and melting phenomena appear to superimpose the exact effects experimental conditions have on fusion enthalpy, measurements are not yet fully understood. In consequence, there still is considerable uncertainty in the literature as regards \(\Delta H_{1}\). [PERSON] [30] and [PERSON] [33] quote seven values from six studies ranging from 37.0 to 47.1 kJ/mol. While the 95% CI (42.7 \(\pm\) 4.0) kJ/mol agrees well with the mid-range value (42.1 kJ/mol), the median of 45.3 kJ/mol  
\begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline
**State of Solute** & \(\delta_{d}\) & \(\delta_{p}\) & \(\delta_{h}\) & \(\delta_{1}\) & **Reference** & \(V_{1}\) & \(T\) \\  & & & & & & **(cm\({}^{3}\)/mol)** & (\({}^{\circ}\)C) \\ \hline subcooled lq. & 18.1 & 12.0 & 27.8 & 35.3 & this work & 109.9 & 25 \\ subcooled lq. & 18.2 & 12.0 & 27.9 & 35.4 & this work & 109.5 & 20 \\ subcooled lq. & 18.0 & 15.7 & 27.4 & 36.4 & [PERSON] [23] & 109.9 & 25 \\ solid particle & 18.6 & 20.4 & 28.2 & 39.5 & [PERSON] et al. [24] & 106.7 & 25 \\ unspecified & 18.0 & 11.7 & 25.5 & 33.3 & [PERSON] et al. [9] & 124.8 & unspecified \\ \hline Units for all solubility parameters are in (MPa)\({}^{0.5}\). Calculations based on ascorbic acid molar volume \(V_{1}\) (\(T\)). Presumed uncertainty \(\Delta\delta_{1}\) = \(\pm 1\) (MPa)\({}^{0.5}\). & & & & \\ \end{tabular}
\end{table}
Table 2: [PERSON] solubility parameters (\(\delta_{d}\), \(\delta_{p}\), \(\delta_{h}\)) and total solubility parameter \(\delta_{1}\) of \(\iota\)-ascorbic acid computed according to [PERSON] and Kreevelen.  
hints at an asymmetric, and thus, non-Gaussian distribution, rendering the use of mean and standard deviation doubtful. For the lack of more consistent data, the rounded mid-range value and half the (max-min) span are taken as \"true\" heat of fusion and its experimental uncertainty, respectively.