Standard Molar Enthalpy of Formation and of Vaporization of Ethyl 3-Oxobutanoate

Abstract

The standard (p° = 0.1 MPa) molar enthalpy of combustion at the temperature 298.15 K of the liquid ethyl 3-oxobutanoate was determined: Δ c H m ° = -3149.76 ± 0.76 kJ.mol -1 , using a static-bomb calorimeter, from which its standard molar enthalpy of formation, in the liquid state, was derived as Δ f H m °(1) = -640.4 ± 1.1 kJ.mol -1 . The standard molar enthalpy of vaporization, at the temperature 298.15 K, determined by microcalorimetry, was found to be Δ l g H m ° = 54.18 ± 0.96 kJ.mol -1 . The standard molar enthalpy of formation of ethyl 3-oxobutanoate was derived for the gaseous keto-enol equilibrium mixture and for the gaseous keto form.