Editing Nitric acid (section)

===Structure and bonding===
[[Image:Nitric acid resonance.svg|thumb|upright=1.2|Two major resonance representations of {{chem2|HNO3}}]]
The two terminal N–O bonds are nearly equivalent and relatively short, at 1.20 and 1.21 Å.<ref name="CEAF">{{ cite journal | title = Microwave spectrum of DNO<sub>3</sub>, and average structures of nitric and nitrous acids | first1 = A. P. | last1 = Cox | first2 = M. C. | last2 = Ellis | first3 = C. J. | last3 = Attfield | first4 = A. C. | last4 = Ferris | journal = [[Journal of Molecular Structure]] | year = 1994 | volume = 320 | issue = 1–2 | pages = 91–106 | doi = 10.1016/0022-2860(93)08008-R | bibcode = 1994JMoSt.320...91C }}</ref> This can be explained by theories of [[Resonance (chemistry)|resonance]]; the two major [[Resonance (chemistry)|canonical forms]] show some [[double bond]] character in these two bonds, causing them to be shorter than N–O [[single bond]]s. The third N–O bond is elongated because its O atom is bonded to H atom,<ref>{{cite journal |first=V. |last=Luzzati |title=Structure cristalline de l'acide nitrique anhydre |language=fr |journal=Acta Crystallographica |year=1951 |volume=4 |issue= 2|pages=120–131 |doi=10.1107/S0365110X51000404|bibcode=1951AcCry...4..120L |doi-access=free }}</ref><ref name=Allan>{{cite journal |first1=D. R. |last1=Allan |first2=W. G. |last2=Marshall |first3=D. J. |last3=Francis |first4=I. D. H. |last4=Oswald |first5=C. R. |last5=Pulham |first6=C. |last6=Spanswick |title=The crystal structures of the low-temperature and high-pressure polymorphs of nitric acid |journal=Dalton Transactions |year=2010 |volume=39 |issue=15 |pages=3736–3743 |doi=10.1039/B923975H |pmid=20354626 |url=https://strathprints.strath.ac.uk/26164/1/The_crystal_structures_of_the_low-temperature_and_high-pressure_polymorphs.pdf |type=Submitted manuscript }}</ref> with a [[bond length]] of 1.41 Å in the gas phase.<ref name="CEAF" /> The molecule is slightly aplanar (the [[nitro group|{{chem2|NO2}}]] and NOH planes are tilted away from each other by 2°) and there is [[Conformational isomerism|restricted rotation]] about the N–OH single bond.<ref name="G&E" /><ref>{{cite journal | title = Microwave Spectrum and Structure of Nitric Acid | first1 = A. P. | last1 = Cox | first2 = J. M. | last2 = Riveros | journal = The Journal of Chemical Physics | year = 1965 | volume = 42 | issue = 9 | page = 3106 | doi = 10.1063/1.1696387 | bibcode = 1965JChPh..42.3106C }}</ref>