Literature values of water-solvent partition coefficients for un-dissociated hydrazoic acid, isocyanic acid and isothiocyanic acid have been used to obtain properties or ‘descriptors’ of the three acids. These descriptors can be used in linear free energy relationships that we have already obtained to predict further values of partition coefficients for a very large number of solvents. The descriptors include the hydrogen-bond acidity, A, and hydrogen-bond basicity, B, of the acids. We have also used literature values of equilibrium constants for 1:1 complexation of the acids with a number of bases to obtain values of our 1:1 hydrogen-bond acidity, α^H₂. There is very good agreement between the two sets of hydrogen-bond acidity. Isothiocyanic acid is a strong hydrogen-bond acid about the same as chloroacetic acid, isocyanic acid is about as strong as acetic acid and hydrogen azide is a moderate-to-weak hydrogen bond acid. The hydrogen-bond basicity of the three acids is very small.