Lab Report Organic Derivatives of Water

...

Reaction with Tollen’s Reagent (Ammoniacal AgNO3)

Tollen’s reagent is known to be a mild oxidizing agent consisting of ammoniacal silver nitrate prepared by dissolving silver nitrate in excess ammonium hydroxide. The latter exists as a complex [Ag(NH3)2^+]. In the presence of heat, the silver ion is reduced to its elemental form that was seen as the mirror adhering to the sides of the test tube. The presence of the said mirror is a positive sign for the reaction. All the samples gave a positive result. A carboxylic acid was produced during the oxidation of 1-butanol, and a ketone was produced for isopropanol. Formation of quinone was the result when phenol reacted with tollens reagent.

Lucas Test: Reaction with HCl-ZnCl2

The rate of the reaction with Lucas reagent differs greatly for a primary, secondary and tertiary alcohol thus, reaction with the Lucas Reagent (HCl/ZnCl2) has been used as a qualitative test for the different types of alcohols. The solubility of the resulting alkyl halides and the mechanism undertaken by the different alcohols caused the difference in rates among the sample. An Sn1 reaction took place when heat was added. Protonation of the Oxygen in the alcohol by H+ donated by the mineral acid occurred. Heterolysis then occurred as carbocation and water molecules come into existence. Then, formation of an insoluble alkyl halide occurred as Cl- attacks the carbocation. Positive reaction was observed. This claim is supported by the presence of cloudy mixture.

Since the reaction undergone Sn1 reaction, the carbocation will prefer the more substitued Carbon. Thus, the tert-butyl alcohol, a tertiary alcohol occurred very rapidly which is then followed by isopropyl, a secondary alcohol, and last in the row is 1-butanol, a primary alcohol.

Reaction with FeCl3

One of the characteristic reaction of phenols is its reaction with ferric chloride which is associated with the formation of colored complexes. This formation may then result to the changes in the energy levels of electrons of reacting compounds, wherein the electrons absorb certain amount of energy. Moreover, as these electrons absorb a wavelength of light (energy), it becomes excited raising itself up to higher energy state. As this molecular phenomena happens, a colored complex is observed macroscopically. The color of the complex corresponds to the color of the wavelength absorbed.

In the experiment conducted, a theoretical result would be the formation of violet complex. It has been observed that our group has obtained a different result. It might be because the chemicals are stocked or there has been a error done during the conduct of the experiment.

Chemical Reactivity: Iodoform Test

Iodoform test is used to detect whether a compound contains a methyl group directed connected to the carbon with the hydroxyl group. In the experiment conducted, samll amount of alcohol and the iodine solution was allowed to react. Addition of hydroxide solution followed. Obtaining a very pale yellow precipitate (CHl3) is an indication of a positive result.

The latter is a characteristic reaction among methyl with alcohols. The formation of the said precipitate is an indication of a positive result because the methyl in the compound reacts with iodine forming the precipitate.

- Conclusion

A molecule of water contains an Oxygen and Hydrogens atoms. Derivatives of water also contain the same atoms with addition of other atoms. These water derivatives are allowed to react with certain reagents or undergo certain tests and come up with theoritical observations. These theoritical observations are due to the characteristics a certain derivative of water has. Nevertheless, the above results are obtained durong the conduct of the experiment. Some gave positive result and some did not which may be because of certain factors such as experimental errors.

...