The vapour pressure of protactinium pentabromide
Abstract
The vapour pressure of protactinium pentabromide, measured using a silica-membrane gauge, is represented by equations (i) and (ii). Interpretation of the experimental results yields the following thermodynamic para- In P(atm)=(19·27 ± 0·8)–(12 399 ± 44)(1/T)(491–556 K)(i), In P(atm)=(11·61 ± 0·02)–(8 136 ± 13)(1/T)(556–635 K)(ii) meters: ΔHs, = 103·1 ± 0·4 kJ mol–1; ΔSs, = 160·2 ± 0·8 J K–1 mol–1; ΔHe= 67·6 ± 0·1 kJ mol–1ΔSe= 96·6 ± 0·4 J K–1 mol–1; ΔHf= 35·40 ± 0·4 kJ mol–1; and ΔSf= 63·6 ± 0·4 J K–1 mol–1. The extrapolated boiling point is 701 K.