Observations for glucose sucrose and dextrin in water, molischs reagent and H2SO4
When glucose, sucrose, and dextrin are added to water, they will dissolve to form clear solutions.
When Molisch's reagent is added to glucose, sucrose, and dextrin solutions, a purple ring or color change will appear at the interface of the two liquids, indicating the presence of carbohydrates.
When concentrated sulfuric acid (H2SO4) is added to glucose, sucrose, and dextrin solutions, a brown color will form, indicating the presence of carbohydrates. With the addition of H2SO4, a dehydration reaction occurs, resulting in the formation of furfural compounds which give the brown color.