Reconocimiento de Alcoholes y Fenoles

Introduction to Alcohol and Phenol Recognition Practice

Overview of Participants and Objectives

• Camilo Pobea and Hugo Leguizamón introduce themselves as chemistry lab instructors. They outline the goal of the practice: to recognize primary, secondary, tertiary alcohols, and phenols in a laboratory setting.

Safety Preparations

• The instructors confirm that all necessary biosecurity elements are in place before starting the experiment. This includes having all reagents ready in the extraction hood.

Reagents for Identification

List of Chemicals Used

• The main reagents for this practice include:

• Ethanol (primary alcohol)

• Isopropanol (secondary alcohol)

• Tert-butanol (tertiary alcohol)

• Phenol (for identification purposes)

Testing Methods

Description of Tests

• Three key tests are introduced for identifying different types of alcohols and phenols:

• Nitrochromic test using potassium dichromate with nitric acid.

• Lucas reagent which contains zinc chloride with hydrochloric acid.

• Ferric chloride test for phenols.

Procedure Initiation

Step-by-Step Process

• The procedure begins by taking a test tube and adding one milliliter of ethanol, followed by one milliliter of nitrochromic mixture. The mixture is then agitated to observe color changes indicative of reactions occurring.

Observations from Tests

Reaction Results

• In one instance, tert-butanol does not react when mixed with nitrochromic solution, indicating its classification as a tertiary alcohol.

• A dark brown-violet coloration is observed when phenol reacts with ferric chloride, confirming its presence.

Timing and Reaction Monitoring

Importance of Timing

• Participants are instructed to monitor the time taken for reactions to occur, noting any precipitate formation or color change within the test tubes during experiments on secondary and primary alcohols as well.

Conclusion on Test Specificity

Unique Characteristics

• It is emphasized that the ferric chloride test is exclusive to phenols due to its distinctive dark violet coloration upon reaction completion, highlighting its specificity among other tests conducted during the session.