The Kinetics of the Thermal Decomposition of Nitric Acid in the Liquid Phase

Abstract

The kinetics of the liquid phase decomposition of HNOs in the temperature range 54 to 88°s uggests that the unimolecular decomposition of N2Os which is known to exist in fuming nitric acid solutions plays a significant role in the rate-determining step. A rate mechanism experimentally indistinguishable from that of the N2Os hypothesis involves the product (N02+)-(NOs-). The effect of several inorganic additives, namely, H20, N204, N206, KNOs, KHSO<, NOHSOi, H2SO< and HCIO4, on the rate of decomposition was in agreement with these postulated rate mechanisms. The inhibition of the decomposition rate by various additives tested was found to be insufficient to prevent the eventual attainment of high equilibrium pressures resulting from the decomposition of fuming nitric acid when stored in closed containers for periods of about a month in the temperature range 54 to 88°. Of all the additives tested on both a molal and a weight basis, H20 gave the most pronounced inhibiting effect on HNOa decomposition.

Time Development of Voltage Frequency Dependence of Partial Discharge Activity in Voids

“…The PD arc reacts with the air in the void and the void surface and can produce various acids, which have been found to highly increase the polymeric void surface conductivity [7,8]. Such acids are known to self-decompose into neutral components, nitric acid in particular [9]. The increased surface conductivity due to PD arcs is therefore expected to decrease with time after short-circuiting.…”

Epitaxial (001) BiFeO3 thin-films with excellent ferroelectric properties by chemical solution deposition-the role of gelation

“…The boiling point of pure nitric acid is ~ 83°C at an ambient pressure and the decomposition temperature of liquid phase nitric acid is ~54°-90°C 40 . Critically, little or no gel formed when the precursor coating was heated in a sealed container, indicating that the gelation was promoted by the removal (evaporation) of the HNO 3 reaction product.…”

Flash microwave-assisted solvothermal (FMS) synthesis of photoactive anatase sub-microspheres with hierarchical porosity

“…32 Acids in solution further contribute to pressure rises in closed systems via decomposition processes. 33,34 Indeed, combining non-aqueous solvents with acidic anions has proved key in the formation of microspheres in such MW syntheses without the need of templating agents. [35][36][37] Commercial MW reactors equipped with pressure sensors and capable of controlling the reaction temperature through incident MW power have been successfully employed for MW solvothermal synthesis.…”