Propiedads de alcoholes y fenoles

Solo disponible en BuenasTareas
  • Páginas : 24 (5822 palabras )
  • Descarga(s) : 0
  • Publicado : 21 de marzo de 2011
Leer documento completo
Vista previa del texto

Based on a kind of experiments, there were determined some physical and chemical properties of alcohols and phenols. Solubility test was made for ethanol (C2H5OH), n-butanol (C4H9OH), sec-butanol (C4H9OH), t-butanol (C4H9OH), phenol (Ar-OH), o-nitrophenol(Ar-NO2OH), p- bromophenol (Ar-BrOH), 2,4-dinitrophenol (Ar-(NO2) 2OH) y β-naftol (2AR-OH) in water (H2O), clorhidric acid (HCl) at 5%, sodium hydroxide (NaOH) at 5%, sodium carbonate (Na2CO3) at 5%, sodium bicarbonate (NaHCO3) at 5% and ethylic ether (C2H6O), It was observed that ethanol was solubilized in all mentioned compounds, instead n-butanol it was only soluble in ethylic ether (polarsolvent), this is due to low molecular weight alcohols are very soluble, in the way the carbonated chainlowers its solubility. T-buthilic alcohol is a little bit soluble than sec-butanol, it is due an increase of ramifications in an alcohol, decreases attraction intramolecular forces, so it will be easy to this solvent to break the bonds of compound. A test was made of alcohol ignition withethanol (C2H5OH) and t-butanol (C4H9OH), it was observed a higher intensity of the glow in the tertiary. Lucas reactive test with n-butanol (C4H9OH), sec-butanol (C4H9OH) and t-butanol (C4H9OH), based o reaction speed, showed reactivity order for these three alcohols were 3 °> 2 °> 1 °, due to carbonium ions stability, made to get alkyl halogenure. In Metallic sodium test, basedin reaction time, it was identified that alcohols acidity was 1 °> 2 °> 3 °. In ethanol oxidation reaction with potassium permanganate at 2% at different pH values, it was observed a color change (reaction happens) : Basic pH, occurs MnO4- reaction (VII) to MnO2 (IV), it is showed by a brown color; otherwise at an acid pH, KMnO4 is a strong oxidant agent, due this ethanol oxidationwouldn’t stop in aldehyde production, until get the appropriate carboxylic acid, because of this in acid dissolution MnO4- (VII) was reduced until manganese (II); and in a neutral dissolution a neutral reduction of MnO4- (VII) was only made to the manganese oxide (IV). Another oxidation was made with potassium dichromate, where n-butanol was oxidized forming an aldehyde, sec-butanolformed a ketone and t-butanol didn’t show any reaction, due to its low hydrogen lack. To finish, one of the most phenol identification test, was the reaction with ferric chloride, characterized by an intense color obtained from the solution.
* Identificar la influencia del grupo funcional OH en las propiedades físicas y químicas de los alcoholes y fenoles.

* Observarla solubilidad y velocidades de reacción de algunos alcoholes y fenoles en diferentes solventes.

* Comparar el comportamiento de un alcohol primario, secundario y terciario al reaccionar a través de pruebas como el ensayo con el reactivo de Lucas, la reacción con sodio metálico y la prueba con el reactivo de cerio.

* Analizar la acidez de algunos alcoholes por medio de lareacción con NaOH al 10%.
Los procedimientos se llevaron a cabo de la siguiente manera en las instalaciones de la universidad Santiago de Cali en el laboratorio de inorgánica:
Se utilizaron cuatro alcoholes diferentes, cuatro fenoles diferentes; se les probó la solubilidad en seis solventes. Los cuales se muestran a continuación1.ALCOHOLESY FENOLES SOLVENTES
Etanol Agua
n- butanol HCl 5%
Sec- butanol...
tracking img