Preliminary Test and Solubility Classification of Organic Compounds

3813 Words Jan 18th, 2012 16 Pages
Preliminary Test and Solubility Classification of Organic Compound

Keene Louise Topacio, Christopher Jay Robidillo

The experiment focuses on how to classify organic compounds by its functional groups. It is done by preliminary test and with the solubility test. Preliminary test used two known compounds also the unknowns. Physical state, color, odor, and ignition test were noted. The known compounds are inorganic and organic compounds. A comparison is made from the observation in the unknown sample, by which we had concluded that there were two organic compounds and one inorganic among the unknowns.
In order to have a strong background about the solubility test, we first classify organic compounds of known functional group using
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In order to have a more distinct result a systematic approach can be considered and it is by solubility classification. First is to test the solubility of the unknown in water. Several structural features of the unknown can be deduced if it is water-soluble. It must be of low molar mass and will usually contain no more than four to five carbon atoms, unless it is polyfunctional. Also, it must contain a polar group that will form a hydrogen bond with water, such as the hydroxy group of an alcohol or a carboxylic acid, the amino functionality of an amine, or the carbonyl group of aldehydes or ketones. Esters, amides, and nitriles dissolve to a lesser extent, and acid. chlorides or anhydrides react with water rather than simply dissolving in it. Test in ether for water soluble compounds are also observed this is to identify further the functional groups in ther unknown. On the other hand, alkanes, alkenes, alkynes, and alkyl halides are water-insoluble. Supplementary test such as solubility in hydrochloric acid, then sodium hydroxide, sodium bicarbonate, and finally tested in sulfuric acid must be done accordingly. Solubility in one or more of these acids and bases is defined in terms of the compound being more soluble in base or acid than in water and reflects the presence of an acidic or basic functional group in the water-insoluble unknown compound.
The experiment was divided into two parts and the group