Classification Tests for Carboxylic Acid and Derivatives

1580 Words Mar 17th, 2012 7 Pages
Classification Tests for Carboxylic Acid and Derivatives
Mary Catherine Sarte, John Emmanuel Sy, Allurie Umel,Franklin Yap,
Mary Christine YouIntroduction Carboxylic acids derivatives are simply groupsof compounds that contain a carbonyl group butwith an electronegative atom attached to thecarbon. The difference in the structure leads to amajor change in reactivity. The reactions of thesegroups of compounds involve nucleophilicsubstitution. Although there are abundant kindsof carboxylic acid derivatives, the experimentonly focuses on the common ones: acid halides,acid anhydrides, esters and amides.Carboxylic acids and their derivatives areusually seen in industrial processes and mostbiological pathways. Esters can be seen as fatsand
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Reactions of carboxylic acides also yield esters, salts and acyl chlorides. The experiment done isto test whether the substance is positive for carboxylic acid and derivatives. The reagents used are acylchloride representing acyl halides; acetic anhydride representing acid anhydrides; ethyl acetaterepresenting esters and acetanamide and benzamide representing amides. Specific tests were performed tospecific compounds. Yielding a positive results indicate the presence of the carboxylic acid group.

In another test tube, a mixture of 0.5mlethanol, 1ml water, and 0.2ml of acyl halide oracid anhydride was prepared. 2ml of 20% NaOHsolution was then added. The test tube wascovered with paraffin wax and was shook forseveral minutes. An odor of the formed ester anda formation of two layers were noted.
C.Aminolysis: Anilide Formation
A few drops of acetyl chloride or aceticanhydride was added to 0.5ml of aniline. Themixture was transferred to a new test tubecontaining 5ml water. The formation of aprecipitate was noted.
D.Hydroxamic Acid Test
The preliminary test was done by mixing 2drops of the sample, 1 ml of 95% ethanol and 1MHCL. A drop of 5% FeCl
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solution was added tothe mixture and the color produced was noted. If a color other than yellow was obtained, the testcannot be used. Otherwise, another test wasconducted as follows:2 drops of the sample was added to 2ml of alcoholic NH
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OHHCL and 1ml of KOH. Thesolution was heated in a boiling water bath for
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