The idea of hydrogen in the nascent state having chemical properties different from those of molecular hydrogen developed the mid-19th century. Alexander Williamson repeatedly refers to nascent hydrogen in his textbook Chemistry for Students, for example writing of the substitution reaction of carbon tetrachloride with hydrogen to form products such as chloroform and dichloromethane that the "hydrogen must for this purpose be in the nascent state, as free hydrogen does not produce the effect".[4] Williamson also describes the use of nascent hydrogen in the earlier work of Marcellin Berthelot.[5] Franchot published a paper on the concept in 1896,[6] which drew a strongly worded response from Tommasi who pointed to his own work that concluded "nascent hydrogen is nothing else than H + x calories".[7]
The term "nascent hydrogen" continued to be invoked into the 20th century.[8]
So, hydrogen can be conveniently produced at low or high pH, according to the volatility of the species to be detected. Acid conditions in the Marsh test promote the fast escape of the arsine gas (AsH3), while under hyperalkaline solution, the degassing of the reduced ammonia (NH3) is greatly facilitated (the ammonium ion NH+ 4 being soluble in aqueous solution under acidic conditions).
^Laborda, F.; Bolea, E.; Baranguan, M. T.; Castillo, J. R. (2002). "Hydride generation in analytical chemistry and nascent hydrogen: when is it going to be over?". Spectrochim. Acta B. 57 (4): 797–802. Bibcode:2002AcSpe..57..797L. doi:10.1016/S0584-8547(02)00010-1.
^Fábos, Viktória; Yuen, Alexander K. L.; Masters, Anthony F.; Maschmeyer, Thomas (2012). "Exploring the myth of nascent hydrogen and its implications for biomass conversions". Chem. Asian J.7 (11): 2629–2637. doi:10.1002/asia.201200557. PMID 22952036.
^Johnson, William H. (31 December 1875). "II. On some remarkable changes produced in iron and steel by the action of hydrogen and acids" (PDF). Proceedings of the Royal Society of London. 23 (156–163): 168–179. doi:10.1098/rspl.1874.0024. eISSN 2053-9126. ISSN 0370-1662. JSTOR 113285. S2CID 97579399.
nascent, hydrogen, outdated, concept, organic, chemistry, that, once, invoked, explain, dissolving, metal, reactions, such, clemmensen, reduction, bouveault, blanc, reduction, since, organic, compounds, react, with, special, state, hydrogen, postulated, unders. Nascent hydrogen is an outdated concept in organic chemistry that was once invoked to explain dissolving metal reactions such as the Clemmensen reduction and the Bouveault Blanc reduction Since organic compounds do not react with H2 a special state of hydrogen was postulated It is now understood that dissolving metal reactions occur at the metal surface and the concept of nascent hydrogen has been discredited in organic chemistry 1 2 However the formation of atomic hydrogen is largely invoked in inorganic chemistry and corrosion sciences to explain hydrogen embrittlement in metals exposed to electrolysis and anaerobic corrosion e g dissolution of zinc in strong acids HCl and aluminium in strong bases NaOH The mechanism of hydrogen embrittlement was first proposed by Johnson 1875 3 The inability of hydrogen atoms to react with organic reagents in organic solvents does not exclude the transient formation of hydrogen atoms capable to immediately diffuse into the crystal lattice of common metals steel titanium different from these of the platinoid group Pt Pd Rh Ru Ni which are well known to dissociate molecular dihydrogen H2 into atomic hydrogen Contents 1 History 2 Reducing agents at low and high pH 3 See also 4 References 5 Further readingHistory EditThe idea of hydrogen in the nascent state having chemical properties different from those of molecular hydrogen developed the mid 19th century Alexander Williamson repeatedly refers to nascent hydrogen in his textbook Chemistry for Students for example writing of the substitution reaction of carbon tetrachloride with hydrogen to form products such as chloroform and dichloromethane that the hydrogen must for this purpose be in the nascent state as free hydrogen does not produce the effect 4 Williamson also describes the use of nascent hydrogen in the earlier work of Marcellin Berthelot 5 Franchot published a paper on the concept in 1896 6 which drew a strongly worded response from Tommasi who pointed to his own work that concluded nascent hydrogen is nothing else than H x calories 7 The term nascent hydrogen continued to be invoked into the 20th century 8 Reducing agents at low and high pH EditDevarda s alloy alloy of aluminium 45 copper 50 and zinc 5 is a reducing agent that was commonly used in wet analytical chemistry to produce in situ so called nascent hydrogen under alkaline conditions for the determination of nitrates NO 3 after their reduction into ammonia NH3 In the Marsh test used for arsenic determination from the reduction of arsenate AsO3 4 and arsenite AsO3 3 into arsine AsH3 hydrogen is generated by contacting zinc powder with hydrochloric acid So hydrogen can be conveniently produced at low or high pH according to the volatility of the species to be detected Acid conditions in the Marsh test promote the fast escape of the arsine gas AsH3 while under hyperalkaline solution the degassing of the reduced ammonia NH3 is greatly facilitated the ammonium ion NH 4 being soluble in aqueous solution under acidic conditions See also EditAtomic hydrogen weldingReferences Edit Laborda F Bolea E Baranguan M T Castillo J R 2002 Hydride generation in analytical chemistry and nascent hydrogen when is it going to be over Spectrochim Acta B 57 4 797 802 Bibcode 2002AcSpe 57 797L doi 10 1016 S0584 8547 02 00010 1 Fabos Viktoria Yuen Alexander K L Masters Anthony F Maschmeyer Thomas 2012 Exploring the myth of nascent hydrogen and its implications for biomass conversions Chem Asian J 7 11 2629 2637 doi 10 1002 asia 201200557 PMID 22952036 Johnson William H 31 December 1875 II On some remarkable changes produced in iron and steel by the action of hydrogen and acids PDF Proceedings of the Royal Society of London 23 156 163 168 179 doi 10 1098 rspl 1874 0024 eISSN 2053 9126 ISSN 0370 1662 JSTOR 113285 S2CID 97579399 Williamson Alexander William 1868 Chemistry for Students Clarendon Press p 139 Williamson Alexander W 1866 Organic chemistry The Chemical News and Journal of Physical Science 13 318 14 17 Franchot R 1896 Nascent hydrogen J Phys Chem 1 2 75 80 doi 10 1021 j150584a002 Tommasi D 1897 Comment on the note of R Franchot entitled Nascent hydrogen J Phys Chem 1 9 555 doi 10 1021 j150591a004 J W McCutcheon 1942 Linoleic Acid Org Synth 22 75 doi 10 15227 orgsyn 022 0075 Further reading EditMeija Juris Alessandro D Ulivo 2008 Nascent hydrogen challenge Analytical and Bioanalytical Chemistry 391 5 1475 6 doi 10 1007 s00216 008 2143 4 ISSN 1618 2642 PMID 18488209 S2CID 19542514 Meija Juris Alessandro D Ulivo 2008 Solution to nascent hydrogen challenge Analytical and Bioanalytical Chemistry 392 5 771 772 doi 10 1007 s00216 008 2356 6 ISSN 1618 2642 PMID 18795271 S2CID 206900604 Retrieved from https en wikipedia org w index php title Nascent hydrogen amp oldid 1164780109, wikipedia, wiki, book, books, library,
