Vapor Pressure of Aqueous Solutions of Nitric Acid

Taylor, Guy B.

doi:10.1021/ie50186a037

Cited by 37 publications

(23 citation statements)

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“…The total nitric acid/water flow was measured by monitoring the pressure change with time in a calibrated volume system. The ratio of vapor pressure of nitric acid to the vapor pressure of water for a 90% solution of nitric acid at 298 K has been previously measured to be 27:1 . Using this ratio, we calculated the flow rate of pure nitric acid.…”

Section: Methodsmentioning

confidence: 99%

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Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)₂^–

et al. 2016

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Dicyanamide [N(CN)2(-)] is a common anionic component of ionic liquids, several of which have shown hypergolic reactivity upon mixing with white-fuming nitric acid. In this study, we explore the thermochemistry of dicyanamide and its reactivity with nitric acid and other molecules to gain insight into the initial stages of the hypergolic phenomenon. We have developed and utilized an electrospray ion source for our selected ion flow tube (SIFT) to generate the dicyanamide anion. We have explored the general reactivity of this ion with several neutral molecules and atoms. Dicyanamide does not show reactivity with O2, H2SO4, H2O2, DBr, HCl, NH3, N2O, SO2, COS, CO2, CH3OH, H2O, CH4, N2, CF4, or SF6 (k < 1 × 10(-12) cm(3)/s); moreover, dicyanamide does not react with N atom, O atom, or electronically excited molecular oxygen (k < 5 × 10(-12) cm(3)/s), and our previous studies showed no reactivity with H atom. However, at 0.45 Torr helium, we observe the adduct of dicyanamide with nitric acid with an effective bimolecular rate constant of 2.7 × 10(-10) cm(3)/s. Intrinsically, dicyanamide is a very stable anion in the gas phase, as illustrated by its lack of reactivity, high electron-binding energy, and low proton affinity. The lack of reactivity of dicyanamide with H2SO4 gives an upper limit for the gas-phase deprotonation enthalpy of the parent compound (HNCNCN; <310 ± 3 kcal/mol). This limit is in agreement with theoretical calculations at the MP2/6-311++G(d,p) level of theory, finding that ΔH298 K(HNCNCN) = 308.5 kcal/mol. Dicyanamide has two different proton acceptor sites. Experimental and computational results indicate that it is lower in energy to protonate the terminal nitrile nitrogen than the central nitrogen. Although proton transfer to dicyanamide was not observed for any of the acidic molecules investigated here, the calculations on dicyanamide with one to three nitric acid molecules reveal that higher-order solvation can favor exothermic proton transfer. Furthermore, the formation of 1,5-dinitrobiuret, proposed to be the key intermediate during the hypergolic ignition of dicyanamide ionic liquids with nitric acid, is investigated by calculation of the reaction coordinate. Our results suggest that solvation dynamics of dicyanamide with nitric acid play an important role in hypergolic ignition and the interactions at the droplet/condensed-phase surface between the two hypergolic liquids are very important. Moreover, dicyanamide exists in the atmosphere of Saturn's moon, Titan; the intrinsic stability of dicyanamide strongly suggests that it may exist in molecular clouds of the interstellar medium, especially in regions where other stable carbon-nitrogen anions have been detected.

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Section: Methodsmentioning

confidence: 99%

“…The ratio of vapor pressure of nitric acid to the vapor pressure of water for a 90% solution of nitric acid at 298 K has been previously measured to be 27:1. 30 Using this ratio, we calculated the flow rate of pure nitric acid.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)₂^–

et al. 2016

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“…We determined this to be true in our contained nAPCI experiment using HNO 3 vapor. Here, different HNO 3 solutions were prepared at varying concentrations (40–70%), each with known vapor pressure . Headspace vapor from each of the prepared HNO 3 solutions was seeded into 10 μL of water plug contained in a removable pulled glass capillary (insert, Figure a).…”

Section: Resultsmentioning

confidence: 99%

“…Here, different HNO 3 solutions were prepared at varying concentrations (40−70%), each with known vapor pressure. 54 Headspace vapor from each of the prepared HNO 3 solutions was seeded into 10 μL of water plug contained in a removable pulled glass capillary (insert, Figure 5a). After 1 h of vapor seeding, the resultant solution in which the HNO 3 vapor has been collected was diluted into 2 mL of water and the pH measured.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Reactive Olfaction Ambient Mass Spectrometry

et al. 2019

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Chemical ionization of organic compounds with negligible vapor pressures (VP) is achieved at atmospheric pressure when the proximal sample is exposed to corona discharge. The vapor-phase analyte is produced through a reactive olfaction process, which is determined to include electrostatic charge induction in the proximal condensed-phase sample, resulting in the liberation of free particles. With no requirement for physical contact, a new contained nano-atmospheric pressure chemical ionization (nAPCI) source was developed that allowed direct mass spectrometry analysis of complex mixtures at a sample consumption rate less than nmol/min. The contained nAPCI source was applied to analyze a wide range of samples including the detection of 1 ng/mL cocaine in serum and 200 pg/mL caffeine in raw urine, as well as the differentiation of chemical composition of perfumes and beverages. Polar (e.g., carminic acid; estimated VP 5.1 × 10–25 kPa) and nonpolar (e.g., vitamin D2; VP 8.5 × 10–11 kPa) compounds were successfully ionized by the contained nAPCI ion source under ambient conditions, with the corresponding ion types of 78 other organic compounds characterized.

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“…the same as equation(4), in which we have supposed that for a given composition, AH is independent of the temperature. The values of AH i as a function of composition have been taken fromTaylor [1925and Mauersberger [1988 determined experimentally the vapor pressures of HNO3 and H20 over a wide range of temperatures (0 ø to -50øC). InFigures 1 and 2…”

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confidence: 99%

Vapor pressures in the ternary system water‐nitric acid‐sulfuric acid at low temperatures

Jaecker-Voirol¹,

Ponche²,

Mirabel³

1990

J. Geophys. Res.

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The partial vapor pressures over liquid or supercooled solutions of water and nitric acid and of water and sulfuric acid are calculated for temperatures below 0°C. From these results the partial vapor pressures over the ternary system water‐nitric acid‐sulfuric acid (liquid or supercooled) have been estimated and compared with the available experimental data of Vandoni at 0°C. Some possible implications for the formation of stratospheric aerosols are also discussed.

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Vapor Pressure of Aqueous Solutions of Nitric Acid

Cited by 37 publications

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Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)₂^–

Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)₂^–

Reactive Olfaction Ambient Mass Spectrometry

Vapor pressures in the ternary system water‐nitric acid‐sulfuric acid at low temperatures

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Vapor Pressure of Aqueous Solutions of Nitric Acid

Cited by 37 publications

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Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)2–

Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)2–

Reactive Olfaction Ambient Mass Spectrometry

Vapor pressures in the ternary system water‐nitric acid‐sulfuric acid at low temperatures

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Product

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Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)₂^–

Experimental and Theoretical Studies of the Reactivity and Thermochemistry of Dicyanamide: N(CN)₂^–