Linear least-squares analysis, enthalpy formation

The derived enthalpies for isomerization of n-BuOH to f-BuOH are —31.9 kJmol (Iq) and —36.7 kJmol (g). From the enthalpies of formation of t-BuOOH, the calculated enthalpies of formation of n-BuOOH are —261.7 kJmol (Iq) and —209.3 kJmol (g). Using the more recently reported enthalpy of formation of teri-BuOOH in the gas phase, the derived enthalpy of formation of n-BuOOH is —198.2 kJmoU. The linear least-squares analysis of the derived liquid enthalpies of formation of n-PrOOH and n-BuOOH and the experimental enthalpy of formation of n-HexOOH gives an intercept of — 161.3 kJ mol and a slope of —23.4 kJmoU, the latter value very close to that for the C3-C6 n-alkanols of —25 kJmoU. From the regression constants, the liquid enthalpy of formation of n-HeptOOH is —325 kJmoU, a value that is less negative, and thus more plausible when compared to its secondary isomers. 

From the data of [1989LAU/BRI], we have four semi-independent measnre-ments to define the three enthalpies of formation of ThF(g), ThF2(g), ThFsfg), as shown in Table VIII-2. We have used a least-square analysis to find the optimal solntions to the over-determined sets of linear equations, nsing either the second-law or the third-law enthalpies, with the results shown in Table VIII-3. 

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