Edward R. Lovejoy, David R. Hanson, L. Gregory Huey
{"title":"SO3与水气相反应动力学及产物","authors":"Edward R. Lovejoy, David R. Hanson, L. Gregory Huey","doi":"10.1021/jp962414d","DOIUrl":null,"url":null,"abstract":"<p >The kinetics of the gas-phase reactions of SO<sub>3</sub> with H<sub>2</sub>O and D<sub>2</sub>O were studied over the temperature range 250?360 K in N<sub>2</sub> with a laminar flow reactor coupled to a chemical ionization mass spectrometer. The SO<sub>3</sub> loss is second order in the water concentration, is independent of pressure (20?80 Torr N<sub>2</sub>, 300 K), and has a strong negative temperature dependence and a significant H/D isotope effect (<i>k</i><sub>H</sub><sub><sub>2</sub></sub><sub>O</sub> ≈ 2<i>k</i><sub>D</sub><sub><sub>2</sub></sub><sub>O</sub>). The yield of sulfuric acid is 1.0 ± 0.5 per SO<sub>3</sub> consumed. These observations are consistent with the rapid association of SO<sub>3</sub> and H<sub>2</sub>O to form the adduct H<sub>2</sub>OSO<sub>3</sub> which reacts with water to produce sulfuric acid. The first-order rate coefficients for loss of SO<sub>3</sub> by reaction with H<sub>2</sub>O and D<sub>2</sub>O are given by <i>k</i><sup>I</sup>(s<sup>-1</sup>) = (2.26 ± 0.85) × 10<sup>-43</sup><i>T</i> exp((6544 ± 106)/<i>T</i>)[H<sub>2</sub>O]<sup>2</sup> and (9.45 ± 2.68) × 10<sup>-44</sup><i>T</i> exp((6573 ± 82)/<i>T</i>)[D<sub>2</sub>O]<sup>2</sup>, where T ≡ K and [H<sub>2</sub>O, D<sub>2</sub>O] ≡ molecule cm<sup>-3</sup>. The errors are the uncertainty at the 95% confidence level for precision only. Analysis of the temperature dependence of the SO<sub>3</sub> loss yields an upper limit for the H<sub>2</sub>O?SO<sub>3</sub> bond enthalpy of 13 kcal mol<sup>-1</sup>. </p>","PeriodicalId":58,"journal":{"name":"The Journal of Physical Chemistry ","volume":null,"pages":null},"PeriodicalIF":2.7810,"publicationDate":"1996-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1021/jp962414d","citationCount":"141","resultStr":"{\"title\":\"Kinetics and Products of the Gas-Phase Reaction of SO3 with Water\",\"authors\":\"Edward R. Lovejoy, David R. Hanson, L. Gregory Huey\",\"doi\":\"10.1021/jp962414d\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >The kinetics of the gas-phase reactions of SO<sub>3</sub> with H<sub>2</sub>O and D<sub>2</sub>O were studied over the temperature range 250?360 K in N<sub>2</sub> with a laminar flow reactor coupled to a chemical ionization mass spectrometer. The SO<sub>3</sub> loss is second order in the water concentration, is independent of pressure (20?80 Torr N<sub>2</sub>, 300 K), and has a strong negative temperature dependence and a significant H/D isotope effect (<i>k</i><sub>H</sub><sub><sub>2</sub></sub><sub>O</sub> ≈ 2<i>k</i><sub>D</sub><sub><sub>2</sub></sub><sub>O</sub>). The yield of sulfuric acid is 1.0 ± 0.5 per SO<sub>3</sub> consumed. These observations are consistent with the rapid association of SO<sub>3</sub> and H<sub>2</sub>O to form the adduct H<sub>2</sub>OSO<sub>3</sub> which reacts with water to produce sulfuric acid. The first-order rate coefficients for loss of SO<sub>3</sub> by reaction with H<sub>2</sub>O and D<sub>2</sub>O are given by <i>k</i><sup>I</sup>(s<sup>-1</sup>) = (2.26 ± 0.85) × 10<sup>-43</sup><i>T</i> exp((6544 ± 106)/<i>T</i>)[H<sub>2</sub>O]<sup>2</sup> and (9.45 ± 2.68) × 10<sup>-44</sup><i>T</i> exp((6573 ± 82)/<i>T</i>)[D<sub>2</sub>O]<sup>2</sup>, where T ≡ K and [H<sub>2</sub>O, D<sub>2</sub>O] ≡ molecule cm<sup>-3</sup>. The errors are the uncertainty at the 95% confidence level for precision only. Analysis of the temperature dependence of the SO<sub>3</sub> loss yields an upper limit for the H<sub>2</sub>O?SO<sub>3</sub> bond enthalpy of 13 kcal mol<sup>-1</sup>. </p>\",\"PeriodicalId\":58,\"journal\":{\"name\":\"The Journal of Physical Chemistry \",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.7810,\"publicationDate\":\"1996-12-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1021/jp962414d\",\"citationCount\":\"141\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"The Journal of Physical Chemistry \",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://pubs.acs.org/doi/10.1021/jp962414d\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Physical Chemistry ","FirstCategoryId":"1","ListUrlMain":"https://pubs.acs.org/doi/10.1021/jp962414d","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Kinetics and Products of the Gas-Phase Reaction of SO3 with Water
The kinetics of the gas-phase reactions of SO3 with H2O and D2O were studied over the temperature range 250?360 K in N2 with a laminar flow reactor coupled to a chemical ionization mass spectrometer. The SO3 loss is second order in the water concentration, is independent of pressure (20?80 Torr N2, 300 K), and has a strong negative temperature dependence and a significant H/D isotope effect (kH2O ≈ 2kD2O). The yield of sulfuric acid is 1.0 ± 0.5 per SO3 consumed. These observations are consistent with the rapid association of SO3 and H2O to form the adduct H2OSO3 which reacts with water to produce sulfuric acid. The first-order rate coefficients for loss of SO3 by reaction with H2O and D2O are given by kI(s-1) = (2.26 ± 0.85) × 10-43T exp((6544 ± 106)/T)[H2O]2 and (9.45 ± 2.68) × 10-44T exp((6573 ± 82)/T)[D2O]2, where T ≡ K and [H2O, D2O] ≡ molecule cm-3. The errors are the uncertainty at the 95% confidence level for precision only. Analysis of the temperature dependence of the SO3 loss yields an upper limit for the H2O?SO3 bond enthalpy of 13 kcal mol-1.