Classification Tests for Hydrocarbons

1410 Words Aug 27th, 2011 6 Pages
Classification Tests for Hydrocarbons

Authors: Goldie Ann Tejada, Allain Joseph S. Templo, Kristinlyn Trajano, Kevin Viray, Quennie Yu

Group 10, 2F-PH, Faculty of Pharmacy, University of Santo Tomas

ABSTRACT

The test compounds undergo different physical and chemical tests to differentiate their intrinsic physical properties and chemical properties. Physical state, color, and odor were noted through simple observation. Miscibility of the test compounds were noted through color change or a warming effect. Flammability was tested by igniting 3-5 drops of the sample in a small evaporating dish. Baeyer’s test and Bromine test were used for tests for active unsaturation. Aromaticity of the compound was determined through nitration.
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Test for Aromaticity is determined through Nitration. The reagents used are HNO3, H2SO4. A Positive result shows a yellow oily layer. The reaction involves electrophilic substitution reaction were in H2SO4 acts as a catalyst and facilitates the formation of nitronium ion (electrophile) and one hydrogen atom in the benzene ring is substituted by the nitronium ion. Oxidation was tested using 2% KMnO4 and 10% NaOH. A Positive result shows a green solution and a brown precipitate. The reaction involves redox reaction and NaOH is used to provide a basic environment. The alkyl group of the aromatic compound is oxidized to a carboxylic acid while Mn7+ is reduced to Mn6+ or Mn4+ depending on the extent of the reaction.

Experimental

Physical state, color, and odor The physical states of the sample were observed at room temperature. Then the color and odor was noted.

Solubility in Concentrated H2SO4 1 ml of concentrated H2SO4 was added to each 6 test tubes. By using dry and calibrated droppers, a drop of each sample was added to the test tubes. Any color change or warming effects were noted.

Ignition Test 3-5 drops of the sample were placed in a small evaporating dish and was lighted by using a match. Presence and color of the flame were noted.
Tests for Active Unsaturation
Baeyer’s Test 2 drops of 2% KMnO4 was added to 5 drops of the sample in a dry test tube. The solution was vigorously shaken and the rate and extent at