Measurements of heats of combustion by flame calorimetry. Part 6.—Formaldehyde glyoxal

Abstract

The heats of combustion of formaldehyde and glyoxal have been measured in the gaseous state at 25°C and 1 atm pressure using a flame calorimeter: ΔH^° _c(formaldehyde, g)=–570.77 ± 0.42 kJ mol^–1, ΔH°(glyoxal, g)=–860.88 ± 0.75 kJ mol^–1. The heats of formation have been related to the dissociation energies of the C—H bond in formaldehyde and the central C—C bond in glyoxal to give 2D(H—CHO)–D(OHC—CHO)= 441.2 ± 1.2 kJ.