Experiment #2: Molisch Test for Carbohydrates (PDF)
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Uploaded by ZippyCharoite
Iqra University
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Summary
This document describes an experiment to identify carbohydrates using the Molisch test. The experiment involves adding a specific reagent to a sample and observing a color change to confirm the presence of the carbohydrate. The experiment demonstrates a chemical test for a class of compounds.
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EXPERIMENT#2 OBJECT: To perform Molisch test for identification of carbohydrates REQUIREMENTS: Test tubes, dropper, test tube holder, H2SO4 (Conc) sample of carbohydrate, Molisch reagent PRINCIPLE In Molisch’s test, the carbohydrate (if present) undergoes dehydration upon the introduction of con...
EXPERIMENT#2 OBJECT: To perform Molisch test for identification of carbohydrates REQUIREMENTS: Test tubes, dropper, test tube holder, H2SO4 (Conc) sample of carbohydrate, Molisch reagent PRINCIPLE In Molisch’s test, the carbohydrate (if present) undergoes dehydration upon the introduction of concentrated hydrochloric or sulphuric acid, resulting in the formation of an aldehyde. This aldehyde undergoes condensation along with two phenol-type molecules (such as α-naphthol, resorcinol, and thymol), resulting in the formation of a purple or reddish-purple coloured complex. PROCEDURE: Take 2 ml of test solution in a clean, dry test tube Add 2 drops of molisch reagent & shake well. Now add H2SO4 dropwise through the sides of the test tube and avoid mixing OBSERVATIONS Reddish violet colored ring is seen at the junction of two liquids. RESULT: The test confirms the presence of carbohydrates in the given sample REMARKS It is a sensitive chemical test for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid to produce an aldehyde derivative which condenses with α- naphthol to form chromogen (red- or purple-colored compound).
