The aqueous solubilities of nitrogen trifluoride and dinitrogen tetrafluoride

Abstract

An apparatus has been designed for the measurement of very low gas solubilities (ca. 1 0-6 mol fraction), allowing fast equilibration between the solute and solvent. The solubilities of NF, (298-31 8 K) and of N2F4 (288-31 8 K) in water have been determined, and the enthalpies and entropies of solution derived.GAS solubilities are relevant to the theoretical understanding of the liquid state and solutions, and to such practical applications as understanding the mechanism of the toxicology of inhaled gases. The anomalous solubility properties of fluorine compounds have proved to be of great importance in the thermodynamic study of aqueous 293 and non-aqueous 4-6 solutions. Ashton ef aL3 have constructed an apparatus specifically designed to measure gas solubilities of the order of mol fraction and they report the solubilities of CF,, SF,, and NF, in water between 275 and 323 K.The aqueous solubilities of NF, and N2F4 are important in the understanding of their toxicity. Toxicological and other studies '-11 have shown that inhalation results in methaemoglobin formation, though it is less certain how far this is a primary lethal factor. Kinetic experiments l1 have demonstrated the considerable oxidative capacity of these gases although in pure water NF, has been shown to be inert even at 406 K. N,F,, after long induction periods (several days at 333 K), undergoes hydrolysis9with an exponential increase in reaction rate. However, exposure to a mixture of 1% (v/v) of NF, in air for 70 min, or to the same concentration of N2F4 for 25 min, was almost invariably lethal to rats.8J0 Since the first stage of intoxication presumably is the dissolution of the gas, the aqueous solubility is clearly important.An apparatus was designed for the measurement of t mmHg = (101-325/760) kPa.

Electrochemical Conversion of Nitrogen Trifluoride as a Gas-to-Solid Cathode in Li Batteries

“…Galvanostatic discharges at 100 mA/g C are shown in Figure S2. While varying degrees of activity were 18 but solubilities in organic solvents have not been widely reported. Our attempts to measure NF 3 solubility in diglyme using a method adapted from that reported previously 12 were challenged due to low solubilities.…”

“…Physicochemical properties of the NF 3 −LiClO 4 (diglyme) system were next investigated in detail. The solubility of NF 3 in H 2 O was previously reported to be as low as 0.8 mM in H 2 O at the partial pressure of 14.70 psi (1 atm) and 298 K, 18 but solubilities in organic solvents have not been widely reported.…”

“…Physicochemical properties of the NF 3 –LiClO 4 (diglyme) system were next investigated in detail. The solubility of NF 3 in H 2 O was previously reported to be as low as 0.8 mM in H 2 O at the partial pressure of 14.70 psi (1 atm) and 298 K, but solubilities in organic solvents have not been widely reported. Our attempts to measure NF 3 solubility in diglyme using a method adapted from that reported previously were challenged because of low solubilities.…”

Environmental and health risk analysis of nitrogen trifluoride (NF3), a toxic and potent greenhouse gas

“…K ow , however, is only used to describe an organic compound about the partition between water phase and oil phase at equilibrium, suggesting that there is no information on K ow . Recent studies on these properties of NF 3 experimentally measured were limited to its vapor pressure [33,34], and water solubility [35,36].…”