Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction
The bromate-bromide reaction was investigated in an acidity range not studied yet. The reaction was followed at the Br2/Br3- isosbestic point (lambda = 446 nm). It was observed a first-order behavior for bromate and bromide ions and a second-order behavior for H+ ion that results in the rate law nu...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Química
2001-01-01
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| Series: | Journal of the Brazilian Chemical Society |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000600014 |
| _version_ | 1818030992421552128 |
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| author | Côrtes Carlos Eduardo S. Faria Roberto B. |
| author_facet | Côrtes Carlos Eduardo S. Faria Roberto B. |
| author_sort | Côrtes Carlos Eduardo S. |
| collection | DOAJ |
| description | The bromate-bromide reaction was investigated in an acidity range not studied yet. The reaction was followed at the Br2/Br3- isosbestic point (lambda = 446 nm). It was observed a first-order behavior for bromate and bromide ions and a second-order behavior for H+ ion that results in the rate law nu = k[BrO3-][Br- ][H+]². This rate law suggests a mechanism involving two successive protonation of bromate followed by the interaction of the intermediate species H2BrO3+ with bromide. These results disagree with the obtained by other authors who observed a second-order behavior for the bromide and first-order for H+, and have proposed intermediate species like H2Br2O3 and HBr2O3-. The second-order for [H+] observed in the range 0.005 <= [H+] <= 2.77 mol L-1 sets down that the pKa of bromic acid, HBrO3, must be lower than -0.5 (T = 25 °C), different from all other values for this pKa proposed in the literature. |
| first_indexed | 2024-12-10T05:44:23Z |
| format | Article |
| id | doaj.art-5af77663cf334f78b5a659e580c5983b |
| institution | Directory Open Access Journal |
| issn | 0103-5053 |
| language | English |
| last_indexed | 2024-12-10T05:44:23Z |
| publishDate | 2001-01-01 |
| publisher | Sociedade Brasileira de Química |
| record_format | Article |
| series | Journal of the Brazilian Chemical Society |
| spelling | doaj.art-5af77663cf334f78b5a659e580c5983b2022-12-22T02:00:12ZengSociedade Brasileira de QuímicaJournal of the Brazilian Chemical Society0103-50532001-01-01126775779Revisiting the Kinetics and Mechanism of Bromate-Bromide ReactionCôrtes Carlos Eduardo S.Faria Roberto B.The bromate-bromide reaction was investigated in an acidity range not studied yet. The reaction was followed at the Br2/Br3- isosbestic point (lambda = 446 nm). It was observed a first-order behavior for bromate and bromide ions and a second-order behavior for H+ ion that results in the rate law nu = k[BrO3-][Br- ][H+]². This rate law suggests a mechanism involving two successive protonation of bromate followed by the interaction of the intermediate species H2BrO3+ with bromide. These results disagree with the obtained by other authors who observed a second-order behavior for the bromide and first-order for H+, and have proposed intermediate species like H2Br2O3 and HBr2O3-. The second-order for [H+] observed in the range 0.005 <= [H+] <= 2.77 mol L-1 sets down that the pKa of bromic acid, HBrO3, must be lower than -0.5 (T = 25 °C), different from all other values for this pKa proposed in the literature.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000600014bromic acidpKabromatebromidekinetics |
| spellingShingle | Côrtes Carlos Eduardo S. Faria Roberto B. Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction Journal of the Brazilian Chemical Society bromic acid pKa bromate bromide kinetics |
| title | Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction |
| title_full | Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction |
| title_fullStr | Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction |
| title_full_unstemmed | Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction |
| title_short | Revisiting the Kinetics and Mechanism of Bromate-Bromide Reaction |
| title_sort | revisiting the kinetics and mechanism of bromate bromide reaction |
| topic | bromic acid pKa bromate bromide kinetics |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532001000600014 |
| work_keys_str_mv | AT cortescarloseduardos revisitingthekineticsandmechanismofbromatebromidereaction AT fariarobertob revisitingthekineticsandmechanismofbromatebromidereaction |