Chemical tests for unknown functional groups

Simple chemical tests Simple qualitative colorimetric tests for ore determination Although wet chemistry looks outdated, it can be useful in an initial assessment of ore, especially under field conditions.

Chemical tests for unknown functional groups

Chemical tests for unknown functional groups

There are no chemical tests in this lab for amines, nitriles, or alkyl halides. If you have one of these functional groups, you must rely on spectral data to determine the functional groups.

Lucas test — alcohols The Lucas reagent contains ZnCl2 in aqueous HCl, which reacts with some alcohols in an SN1 reaction to produce an alkyl chloride. Which it is first formed it appears cloudy because it is immiscible with water; eventually it separates to form an other layer.

The test does not work well on solid alcohols because they do not easily dissolve in the first place, and multifunctional compounds may give unusual results.

Chemical tests for unknown functional groups

Phenols also do not react. The test is positive with secondary, tertiary or benzylic alcohols but negative with primary alcohols. Add about 2 drops of a liquid unknown to 0. Shake vigorously, then allow to stand at room temperature.

If the alcohol is primary, it will simply dissolve in the reagent. Jones test — alcohols The Jones reagent contains CrO3 in sulfuric acid solution, which oxidizes primary alcohols to carboxylic acids and secondary alcohols to ketones.

This reaction is also the basis for the breathalyzer test for drunk drivers. Aldehydes will also be oxidized to carboxylic acids, and will also give a positive result. Phenols do not react or give an unusual reaction in this test.

Dissolve about 10 mg if solid or 2 drops if liquid of unknown in 0. Add one drop of Jones reagent and shake. Primary and secondary alcohols react within 10 seconds to form a blue-green precipitate; tertiary alcohols do not react solution remains orange. Tollen's test — aldehydes In this test the aldehyde is oxidized to a carboxylic acid, reducing silver ions to silver metal.

Ketones cannot be oxidized, so this is a good way to distinguish ketones from aldehydes. Then add about 10 mg if solid or 2 drops if liquid of the unknown and shake well.

Allow to stand at room temperature for ten minutes. Formation of a silver coating on the outside of the test tube is a positive test. Do not allow this mixture to stand overnight — silver fulminate, an explosive compound, may form.The results of the tests on the unknown compound can be matched with the recorded observations of each class to help determine the hydrocarbon functional group of the unknown.

Experimental: The experimental procedure carried out for this lab followed the steps listed in the lab manual.

Long-press on an item to remove items, change colour, auto-arrange, cross-link, copy, and more. Click on a test tube to perform each of the following tests on your unknown. For example, clicking on the tube furthest to the left in the second row would show you the results of testing the water solubility of unknown .

Chemical T ests for Unknowns Chemical tests have been developed as a means of identifying what functional groups are present in an unknown compound. Keywords: solubility classes, classification test, functional groups, aromatic amine, aniline Introduction In identifying unknown compounds, one has to This experiment aims to: undergo series of tests such as preliminary test, Familiarize the students to the different solubility classification test and elemental classification tests used for.

Study Flashcards On Organic Chemistry Classification Tests of Functional Groups at Quickly memorize the terms, phrases and much more. makes it easy to .

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