Standard molar enthalpies of formation of sodium alkoxides

The molar enthalpies of solution of sodium in methanol, ethanol, and n-propanol and of sodium alkoxides in their corresponding alcohols were measured at T = 298.15 K using an isoperibol solution calorimeter. From these results and other auxiliary data, the standard molar enthalpies of formation ΔfHm∘(RONa,cr) of sodium methoxide, sodium ethoxide, and sodium n-propoxide were calculated and found to be {(−366.21 ± 1.38), (−413.39 ± 1.45), and (−441.57 ± 1.18)} kJ · mol−1, respectively. A linear correlation has been found between ΔfHm∘(RONa)andΔfHm∘(ROH) for R = n-alkyl, enabling the prediction of data for other sodium alkoxides.