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BIBTEX RIS

Decaimento de íons cianato e a formação de carbamato de etila

2013; Brazilian Chemical Society; Volume: 36; Issue: 8 Linguagem: Inglês

10.1590/s0100-40422013000800004

ISSN

1678-7064

Autores

Alexandre Ataíde da Silva, Thiago Hideyuki Kobe Ohe, Douglas Wagner Franco,

Tópico(s)

Pesticide and Herbicide Environmental Studies

Resumo

CYANATE ION DECAY AND ETHYL CARBAMATE FORMATION.Cyanate ion stability was studied in aqueous/ethanolic solutions, pH = 4.5 (CH 3 COOH/NaCH 3 COO), at different temperatures.Following the decay [(OCN) -] versus time, in the presence of excess C 2 H 5 OH, the rate constant for this reaction (k 1 ) was calculated as (2.5 ± 0.3) x 10 -4 s -1 at 25 °C, for 0 ≤ [C 2 H 5 OH] ≤ 13.7 x 10 -1 mol L -1 .For [C 2 H 5 OH] ≥ 2.0 mol L -1 a decrease in the numerical value of k 1 was observed, reaching 5.2 x 10 -5 s -1 when [CH 3 CH 2 OH] = 13.7 mol L -1 .Variations in the kinetic parameter values ΔH 1 ‡ , ΔS 1 ‡ and ΔG 1 ‡ for the cyanate ion decay reaction were observed for solutions at different ethanol concentrations.

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