scholarly journals A simple and expeditious process for the estimation of nitric acid in water analysis, with some remarks on the estimation of nitrous acid

The Analyst ◽  
1881 ◽  
Vol 6 (March) ◽  
pp. 36
Author(s):  
M. Whitley Williams
Keyword(s):  
Nitric Acid ◽  
Water Analysis ◽  
Nitrous Acid

scholarly journals IX. The electric conductivity of nitric acid

1898 ◽  
Vol 191 ◽  
pp. 365-398 ◽  
Keyword(s):  
Nitric Acid ◽  
Physical Properties ◽  
Nitrous Acid ◽  
Internal Resistance ◽  
The Other ◽  
Reasonable Degree ◽  
Mineral Acids ◽  
Artificial Illumination ◽  
The Subject ◽  
Deep Green

Of the commoner mineral acids the chemical changes of Nitric Acid, from their evident complexity, have formed the subject of numerous memoirs, while those of sulphuric acid, from their assumed simplicity, have been to some degree neglected; on the other hand, the physical properties of the latter have been studied with considerable elaboration, while those of the former have been passed over, doubtless on account of the corrosive nature of the acid and the difficulty of preparing and preserving it in a reasonable degree of purity. Further, with certain exceptions, the alterations in physical properties induced by the products of reduction, be they nitrogen peroxide or nitrous acid, either singly or conjointly, have attracted but little attention, though it is a common matter of observation that the current intensity of a Grove’s or other cell containing nitric acid remains constant, even though the fuming acid, originally colourless or red, has become of a deep green tint. It is more than probable that of the factors of Ohm’s law, both the E. M. F. and internal resistance are continually varying. At the earliest stages of the enquiry it was found that the passage of a few bubbles of nitric oxide gas into a considerable volume of nitric acid produced an alteration of one percent, in the resistance, and the same result could be effected to a less degree by exposure to sunlight, and to a still less degree by exposure to artificial illumination. Therefore, we determined to investigate the alterations of conductivity produced by changes of concentration and temperature in samples of acid purified with necessary precautions, more especially as former workers upon the subject have either used samples of acid confessedly impure, or have been silent as to any method of purification, or have adopted no special care in dealing with a substance so susceptible of polarisation.

Coupling between the Tropospheric Photochemistry of Nitrous Acid (HONO) and Nitric Acid (HNO3)

2006 ◽  
Vol 3 (1) ◽  
pp. 31 ◽  
Author(s):  
Kevin C. Clemitshaw
Keyword(s):  
Nitric Acid ◽  
Hydroxyl Radicals ◽  
Nitrous Acid ◽  
Snow Pack ◽  
Rural And Remote ◽  
Sources And Sinks ◽  
Tropospheric Photochemistry ◽  
Recent Developments ◽  
Urban Rural ◽  
And Migration

Environmental Context.Nitrous acid (HONO) is formed in the troposphere in urban, rural and remote environments via several uncertain heterogeneous and photochemical processes that involve nitric acid (HNO3). A recently recognised process is initiated by the deposition and migration of HNO3 within snow-pack surfaces to form nitrate anions (NO3−). Photo-reduction of NO3− followed by acidification of the nitrite (NO2−) photo-product leads to emissions of gas-phase HONO. Seasonal observations at Halley, Antarctica are consistent with the formation of HONO via this process, which is potentially of global significance because much of the Earth’s land (and sea) surface is covered with snow and is sunlit for much of the year. Both HONO and HNO3 significantly influence the production of ozone (O3), which acts as a greenhouse gas in the troposphere, via their respective roles as a source of hydroxyl radicals (OH•) and as a sink for OH• and nitrogen dioxide (NO2). Abstract.The tropospheric photochemistry of nitrous acid (HONO) and its coupling with that of nitric acid (HNO3) in urban, rural and remote atmospheres are highlighted in terms of established and uncertain homogeneous and heterogeneous sources and sinks, together with known and potential effects and impacts. Observations made at Halley, Antarctica, via optical detection of an azo dye derivative of HONO are consistent with snow-pack photochemical production of HONO, which has potential significance for the production of hydroxyl radicals (OH•) and ozone (O3) on regional and global scales. Recent developments in measurement methods for HONO and HNO3 are also highlighted. It is now timely to conduct a formal intercomparison of the methods in order to evaluate and enhance their capabilities, and to validate the growing body of HONO and HNO3 data obtained in urban, rural and remote locations.

Can nitrous acid contribute to atmospheric new particle formation from nitric acid and water?

2020 ◽  
Vol 44 (36) ◽  
pp. 15625-15635
Author(s):  
Shuang Ni ◽  
Feng-Yang Bai ◽  
Xiu-Mei Pan
Keyword(s):  
Optical Properties ◽  
Nitric Acid ◽  
Temperature Dependence ◽  
Nitrous Acid ◽  
Intermolecular Forces ◽  
Particle Formation ◽  
New Particle Formation

The properties of (HNO3)(HONO)(H2O)n (n = 1–6) clusters are reported including thermodynamics, structures, temperature-dependence, intermolecular forces, optical properties, and evaporation rates.

Basicity and acidity promote hydrolysis of methyl nitrate in aqueous aerosols

2020 ◽  
Author(s):  
Fatemeh Keshavarz ◽  
Theo Kurtén ◽  
Hanna Vehkamäki
Keyword(s):  
Nitric Acid ◽  
Nitrous Acid ◽  
Rate Coefficients ◽  
Alkyl Nitrates ◽  
Hydronium Ions ◽  
Hydroxyl Ion ◽  
Solvent Model ◽  
Methyl Nitrate ◽  
Hydrolysis Of ◽  
Aqueous Aerosols

<p>The chemistry of organic nitrates (ONs), also known as alkyl nitrates (RONO<sub>2</sub>), controls the lifetime of nitrogen oxides in continental areas, which in turn affects air quality and varies ozone concentration throughout the troposphere. ONs can be emitted to the troposphere from marine sources. Also, they can be produced in the atmosphere through addition of NO to peroxy radicals or through the reaction of NO<sub>3</sub> radicals with volatile organic compounds. Atmospheric ONs may subsequently undergo oxidation or photolysis, in both gas and aerosol phases, or hydrolysis in aqueous aerosols. Though some recent studies have believed acid-catalysis promotes hydrolysis of ONs, earlier studies have claimed that acids have no effect on ON hydrolysis, and that it is the hydroxyl ion that can improve the hydrolysis process. The limited number of experimental studies performed so far have left this conflict with no appropriate answer, as mechanistic insight and full kinetics details have been partially or completely missing for the studied ONs. We report the detailed mechanism of methyl nitrate hydrolysis in acidic, neutral and basic conditions, in addition to analyzing the degradation of methyl nitrate into formaldehyde and nitrous acid in the presence of water and hydronium ions. According to the potential energy surfaces obtained at the CCSD(T)/cc-pVDZ//ωB97X-D/def2-TZVP level of theory (including the SMD solvent model) along with the rate coefficients estimated using asymmetric Eckart tunneling-corrected transition state theory (TST), mediation of water molecules and hydronium ions hinders degradation of methyl nitrate into formaldehyde and nitrous acid and, in general, this decomposition reaction is kinetically unfavorable. Furthermore, neutral hydrolysis of methyl nitrate is extremely slow with pseudo-first order rate coefficients (k; 298 K and 1 atm) falling below 10<sup>-27</sup> s<sup>-1</sup>. Similarly, hydrolysis of methyl nitrate by hydronium ions is observed to be extremely slow (k < 10<sup>-27</sup> s<sup>-1</sup>). However, under acidic conditions, protonation of methyl nitrate is quite feasible with the protonation Gibbs free energy of -429.1 kJ mol<sup>-1</sup>, at 298 K and 1 atm, and protonated methyl nitrate can hydrolyze into protonated methanol and nitric acid much faster relative to the hydronium ion-based and neutral hydrolysis (k = 3.83 s<sup>-1</sup>). On the other hand, the hydroxyl ions generated under basic conditions can hydrolyze methyl nitrate readily to give methanol and nitric acid (k = 6.63 × 10<sup>3</sup> s<sup>-1</sup>), or formaldehyde, nitrate and water (k = 9.40 × 10<sup>6</sup> s<sup>-1</sup>). In addition, regardless of the limitation on the rate of solvent-phase chemical reactions by the rate of diffusion, basic hydrolysis can produce methoxy ions and nitric acid quite fast (k = 8.95 × 10<sup>9</sup> s<sup>-1</sup>). In other words, methyl nitrate hydrolysis is faster in basic aerosols (i.e. some marine aerosols) and, to a less extent, in highly acidic aqueous aerosols (e.g. haze and urban aerosols).       </p>

Nitrous acid generation from radiolysis of nitric acid aqueous solution under gas flow condition

2016 ◽  
Vol 54 (2) ◽  
pp. 182-187
Author(s):  
Daisuke Watanabe ◽  
Yoichi Wada ◽  
Akira Sasahira ◽  
Masashi Itori ◽  
Tetsunari Ebina
Keyword(s):  
Aqueous Solution ◽  
Nitric Acid ◽  
Flow Condition ◽  
Nitrous Acid ◽  
Gas Flow ◽  
Acid Generation ◽  
Acid Aqueous Solution

VI. The conditions of the formation and decomposition of nitrous acid

1893 ◽  
Vol 52 (315-320) ◽  
pp. 27-55 ◽  
Keyword(s):  
Nitric Acid ◽  
Nitrous Acid

Throughout the whole science of chemistry there is possibly no reagent so frequently represented as taking part in various trans­formations, but of which so little definite is known, as nitrous acid. In many text-books its properties are cursorily discussed in a few lines, while some writers have gone so far as to deny its existence altogether even in the presence of nitric acid.

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